Early kidney damage induced by subchronic exposure to PM2.5 in rats

Air pollution aggravates renal ischaemia-reperfusion-induced acute kidney injury

Chronic kidney disease (CKD) has emerged as a significant global public health concern. Recent epidemiological studies have highlighted the link between exposure to fine particulate matter (PM2.5) and a decline in renal function. PM2.5 exerts harmful effects on various organs through oxidative stress and inflammation. Acute kidney injury (AKI) resulting from ischaemia-reperfusion injury (IRI) involves biological processes similar to those involved in PM2.5 toxicity and is a known risk factor for CKD. The objective of this study was to investigate the impact of PM2.5 exposure on IRI-induced AKI. Through a unique environmentally controlled setup, mice were exposed to urban PM2.5 or filtered air for 12 weeks before IRI followed by euthanasia 48 h after surgery. Animals exposed to PM2.5 and IRI exhibited reduced glomerular filtration, impaired urine concentration ability, and significant tubular damage. Further, PM2.5 aggravated local innate immune responses and mitochondrial dysfunction, as well as enhancing cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway activation. This increased renal senescence and suppressed the anti-ageing protein klotho, leading to early fibrotic changes. In vitro studies using proximal tubular epithelial cells exposed to PM2.5 and hypoxia/reoxygenation revealed heightened activation of the STING pathway triggered by cytoplasmic mitochondrial DNA, resulting in increased tubular damage and a pro-inflammatory phenotype. In summary, our findings imply a role for PM2.5 in sensitising proximal tubular epithelial cells to IRI-induced damage, suggesting a plausible association between PM2.5 exposure and heightened susceptibility to CKD in individuals experiencing AKI. Strategies aimed at reducing PM2.5 concentrations and implementing preventive measures may improve outcomes for AKI patients and mitigate the progression from AKI to CKD. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Air pollution and kidney cancer risk: a systematic review and meta-analysis

BACKGROUND

Although several risk factors of kidney cancer have already been well-addressed, many remain underappreciated, such as chronic exposure to air pollution. This systematic review and meta-analysis aims to assess the association between air pollutant exposure and the risk of kidney cancer.

METHODS

With an exhaustive search equation including keywords related to air pollution and kidney cancer on EMBASE, PubMed, Web of science, Cochrane Library and CINAHL database, we identified all relevant articles published before March 23rd, 2023 (Prospero registration number: CRD42020187956). Using random-effects meta-analysis, we present pooled hazard ratios (with their respective 95% confidence interval) associated with a 10 µg/m3 increase in each pollutant level. Heterogeneity was quantified by the I2 statistic. Risks of methodological and publication bias were also both assessed using appropriate tools.

RESULTS

Of the 1919 records identified, our review included 19 articles (13 cohort, 5 registry-based and 1 case-control studies), of which 9 were suitable for the meta-analysis. We found a significantly increased risk of kidney cancer incidence for a 10 μg/m3 elevation of both particulate matter of less than 10 µm (PM10) (HR = 1.29 [1.10; 1.51], I2 = 0%, p = 0.002) and nitrogen dioxide (NO2) (HR = 1.10 [1.03; 1.18], I2 = 20%, p = 0.004). Secondary analyses also suggest an increased risk of kidney cancer-related morbidity-mortality associated with PM10 exposure.

CONCLUSIONS

Overall, our findings suggest a potential association between exposure to increased levels of PM10 and NO2 and the risk of kidney cancer. These results should nonetheless be interpreted with caution due to the limited number of included studies and their significant risk of methodological bias.

Occupational particle exposure and chronic kidney disease: a cohort study in Swedish construction workers

OBJECTIVES

Increasing epidemiological and experimental evidence suggests that particle exposure is an environmental risk factor for chronic kidney disease (CKD). However, only a few case-control studies have investigated this association in an occupational setting. Hence, our objective was to investigate associations between particle exposure and CKD in a large cohort of Swedish construction workers.

METHODS

We performed a retrospective cohort study in the Swedish Construction Workers' Cohort, recruited 1971-1993 (n=286 089). A job-exposure matrix was used to identify workers exposed to nine different particulate exposures, which were combined into three main categories (inorganic dust and fumes, wood dust and fibres). Incident CKD and start of renal replacement therapy (RRT) were obtained from validated national registries until 2021 and analysed using adjusted Cox proportional hazards models.

RESULTS

Exposure to inorganic dust and fumes was associated with an increased risk of CKD and RRT during working age (adjusted HR for CKD at age <65 years 1.15, 95% CI 1.05 to 1.26). The elevated risk did not persist after retirement age. Exposure to cement dust, concrete dust and diesel exhaust was associated with CKD. Elevated HRs were also found for quartz dust and welding fumes.

CONCLUSIONS

Workers exposed to inorganic particles seem to be at elevated risk of CKD and RRT. Our results are in line with previous evidence of renal effects of ambient air pollution and warrant further efforts to reduce occupational and ambient particle exposure.

Short-term association between air pollution and daily genitourinary disorder admissions in Lanzhou, China

The aim of this study was to determine the relationship between short-term exposure to ambient air pollution and the number of daily hospital admissions for genitourinary disorders in Lanzhou. Hospital admission data and air pollutants, including PM2.5, PM10, SO2, NO2, O38h and CO, were obtained from the period 2013 to 2020. A generalized additive model (GAM) combined with distribution lag nonlinear model (DLNM) based on quasi-Poisson distribution was used by the controlling for trends, weather, weekdays and holidays. Short-term exposure to PM2.5, NO2 and CO increased the risk of genitourinary disorder admissions with RR of 1.0096 (95% CI 1.0002-1.0190), 1.0255 (95% CI 1.0123-1.0389) and 1.0686 (95% CI 1.0083-1.1326), respectively. PM10, O38h and SO2 have no significant effect on genitourinary disorders. PM2.5 and NO2 are more strongly correlated in female and ≥ 65 years patients. CO is more strongly correlated in male and < 65 years patients. PM2.5, NO2 and CO are risk factors for genitourinary morbidity, and public health interventions should be strengthened to protect vulnerable populations.

Association of fine particulate matter (PM2.5) exposure and chronic kidney disease outcomes: a systematic review and meta-analysis

Several studies have reported an increased risk of chronic kidney disease (CKD) outcomes after long-term exposure (more than 1 year) to particulate matter with an aerodynamic diameter of ≤ 2.5 µm (PM2.5). However, the conclusions remain inconsistent. Therefore, we conducted this meta-analysis to examine the association between long-term PM2.5 exposure and CKD outcomes. A literature search was conducted in PubMed, Scopus, Cochrane Central Register of Controlled trials, and Embase for relevant studies published until August 10, 2023. The main outcomes were incidence and prevalence of CKD as well as incidence of end-stage kidney disease (ESKD). The random-effect model meta-analyses were used to estimate the risk of each outcome among studies. Twenty two studies were identified, including 14 cohort studies, and 8 cross-sectional studies, with a total of 7,967,388 participants. This meta-analysis revealed that each 10 μg/m3 increment in PM2.5 was significantly associated with increased risks of both incidence and prevalence of CKD [adjusted odds ratio (OR) 1.31 (95% confidence interval (CI) 1.24 to 1.40), adjusted OR 1.31 (95% CI 1.03 to 1.67), respectively]. In addition, the relationship with ESKD incidence is suggestive of increased risk but not conclusive (adjusted OR 1.16; 95% CI 1.00 to 1.36). The incidence and prevalence of CKD outcomes had a consistent association across all subgroups and adjustment variables. Our study observed an association between long-term PM2.5 exposure and the risks of CKD. However, more dedicated studies are required to show causation that warrants urgent action on PM2.5 to mitigate the global burden of CKD.

Recent ambient temperature and fine particulate matter (PM2.5) exposure is associated with urinary kidney injury biomarkers in children

BACKGROUND

Limited research has examined associations between exposure to ambient temperature, air pollution, and kidney function or injury during the preadolescent period. We examined associations between exposure to ambient temperature and particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5) with preadolescent estimated glomerular filtration rate (eGFR) and urinary kidney injury biomarkers.

METHODS

Participants included 437 children without cardiovascular or kidney disease enrolled in the Programming Research in Obesity, Growth, Environment and Social Stressors birth cohort study in Mexico City. eGFR and urinary kidney injury biomarkers were assessed at 8-12 years. Validated satellite-based spatio-temporal models were used to estimate mean daily temperature and PM2.5 levels at each participant's residence 7- and 30-days prior to the date of visit. Linear regression and distributed lag nonlinear models (DLNM) were used to examine associations between daily mean temperature and PM2.5 exposure and kidney outcomes, adjusted for covariates.

RESULTS

In single linear regressions, higher seven-day average PM2.5 was associated with higher urinary alpha-1-microglobulin and eGFR. In DLNM analyses, higher temperature exposure in the seven days prior to date of visit was associated with a decrease in urinary cystatin C of -0.56 ng/mL (95 % confidence interval (CI): -1.08, -0.04) and in osteopontin of -0.08 ng/mL (95 % CI: -0.15, -0.001). PM2.5 exposure over the seven days prior to date of visit was associated with an increase in eGFR of 1.77 mL/min/1.73m2 (95 % CI: 0.55, 2.99) and urinary cystatin C of 0.19 ng/mL (95 % CI: 0.03, 0.35).

CONCLUSIONS

Recent exposure to ambient temperature and PM2.5 were associated with increased and decreased urinary kidney injury biomarkers that may reflect subclinical glomerular or tubular injury in children. Further research is required to assess environmental exposures and worsening subclinical kidney injury across development.

The renoprotective effects of hesperidin on kidney injury induced by exposure to severe chronic dust storm particulate matter through inhibiting the Smads/TGF-β1 signaling in rat

Exposure to dust storm particulate matter (PM) is detrimental to kidney tissue. In this study, the impacts of chronic intake of dusty PM were explored as a major objective in a specified compartment to make a real-like dust storm (DS) model, and the role of hesperidin (HSP) as an antioxidant on kidney tissue was assessed in rats. Thirty-two male Wistar rats (200-220 g) were randomly allocated into 4 groups: CA+NS: (clean air and normal saline as a vehicle of HSP). Dusty PM and NS (DS+NS). HSP+ CA: rats received 200 mg/kg of HSP by gavage for 28 days, once daily in addition to exposure to clean air. HSP+DS: HSP plus DS. In DS groups, the animals were exposed to dust storms at a concentration of 5000-8000 μg/m3 in the chamber for 1 h daily, for 4 consecutive weeks, except Thursdays and Fridays. At the end of the experiment, the animals were sacrificed for biochemical, inflammatory, oxidative stress, molecular parameters, and histological evaluation. DS significantly enhanced blood urea nitrogen and creatinine, inflammatory (tumor necrosis factor-α, and interleukin-1β), and oxidative stress indexes. Likewise, a significant increase was seen in mRNA Smads, collagen-I, and transforming growth factor-β1 (TGF-β1) expressions in the kidney. Histological findings showed contracted glomeruli and kidney structure disorder. In addition, Masson's trichrome staining demonstrated renal fibrosis. Nevertheless, HSP could significantly reverse these changes. Our data confirmed that DS results in kidney fibrosis through enhancing Smads/TGF-β1 signaling. However, HSP was able to inhibit these changes as confirmed by histological findings.

Subchronic exposure to PM2.5 induced renal function damage and intestinal microflora changes in rats

BACKGROUND

Exposure to inhalable environmental particulate matter with a diameter of 2.5 µm or smaller (PM2.5) is associated with decreased or impaired kidney function, but the underlying biological mechanisms are not fully understood. Gut microbiota is an emerging key player in the homeostasis regulation of the gut-kidney axis. Few studies have investigated its role in PM2.5 exposure-induced gut-kidney axis homeostasis abnormalities.

METHODS

In this study, a versatile aerosol concentration enrichment system for medium- to long-term whole-body exposure was used to expose Sprague-Dawley rats to filtered air (FA) or concentrated ambient PM2.5 for 12 weeks. A correlation analysis of renal impairment and the intestinal microbiome was performed.

RESULTS

The urine flow rate calculation and renal function analysis showed that PM2.5 exposure significantly impaired renal function and increased the urine flow rate. The fecal microbiota analysis showed that renal impairment and increased urine flow rates were consistent with the reduced estimates of the fecal bacteria Chao1, observed-species, Shannon, and Simpson (richness and diversity indices). Pearson's correlation analysis showed that the estimated bacterial richness and diversity were correlated with the urine flow rate and renal function. The linear discriminant analysis effect size (LEfSe) analysis revealed differences between animals exposed to PM2.5 and FA in 25 bacterial groups. Further correlation of a single bacterial taxon with the urine flow rate and renal function showed that the relative abundances of 30, 29, 21, and 50 distinct bacterial groups were significantly correlated with the urine flow rate, estimated glomerular filtration rate (eGFR), serum cystatin C (CysC), and beta-2 microglobulin (β2-MG), respectively.

CONCLUSION

Subchronic exposure to PM2.5 can cause intestinal ecological disorders, which may, in turn, lead to decreased kidney function or the development of impaired kidney function.

PM2.5 induces renal tubular injury by activating NLRP3-mediated pyroptosis

Fine particulate matter (PM2.5)-related health issues have received increasing attention as a worldwide public health problem, and PM2.5-related chronic kidney disease (CKD) has been emerging over the years. Limited research has focused on the mechanism of PM2.5-induced kidney disease. To investigate the impact of PM2.5 on the kidney and its potential mechanism, we generated a PM2.5-exposed C57BL/6 mouse model by using Shanghai Meteorological and Environment Animal Exposure System (Shanghai-METAS) for 12 weeks, urine, blood and kidney tissues were collected. The pathological changes and the function of the kidney were measured after PM2.5 exposure for 12 weeks. Along with glomerular damage, tubular damage was also severe in PM2.5-induced mice. The results of mRNA-seq indicate that pyroptosis is involved. Pyroptosis is defined as caspase-1-dependent programmed cell death in response to insults. The expression of the nucleotide-binding and oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3), Caspase-1, gasdermin D (GSDMD) and IL-1β was detected. NLRP3 inflammasome activation and subsequent pyroptosis were observed in PM2.5-exposed kidney tissues and PM2.5-exposed Bumpt cells too. At the meantime, the inhibitors of NLRP3 and caspase-1 were applied to the PM2.5 exposed Bumpt cells. It turned out to have a significant rescue effect of the inhibitors. This study revealed new insights into PM2.5-induced kidney injury and specific kidney pathological damage, as well as morphological changes, and defined the important role of pyroptosis in PM2.5-induced kidney dysfunction.

Impact of Particulate Matter With an Aerodynamic Diameter <2.5 μm Concentration on Postoperative Renal Function in Living Kidney Donors

BACKGROUND

Ambient air pollution has become 1 of the most important public health issues worldwide. In particular, particulate matter with an aerodynamic diameter <2.5 μm (PM2.5) is a fatal component of air pollution. We aimed to analyze whether perioperative exposure to PM2.5 is associated with the deterioration of renal function in living kidney donors.

METHODS

This study was conducted on 232 kidney donors with postoperative 2-year glomerular filtration rate (GFR). The GFR was determined by serum creatinine-based method using the Modification of Diet in Renal Disease equation and radionuclide-based method using 99mTc-DTPA renal scintigraphy. Perioperative exposure to PM2.5 was calculated using data from the AIRKOREA System. Multiple linear and logistic regression analyses were performed to estimate the associations between mean PM2.5 concentration and postoperative 2-year GFR.

RESULTS

Postoperative Modification of Diet in Renal Disease-estimated GFRs of kidney donors with low PM2.5 concentrations were significantly higher than those of those with high PM2.5 concentrations. A 1-μg/m3 increase in mean PM2.5 concentration was associated with decreased GFR by 0.20 mL/min/1.73 m2. In addition, a 1-μg/m3 increase in mean PM2.5 concentration was associated with an 11% increased risk of chronic kidney disease stage ≥3 at 2 years after donor nephrectomy.

CONCLUSION

In patients who underwent donor nephrectomy, exposure to PM2.5 negatively affects renal function and is positively associated with the prevalence of chronic kidney disease.

Association of the components of ambient fine particulate matter (PM2.5) and chronic kidney disease prevalence in China

Previous research has implicated PM_2.5 as a potential environmental risk factor for CKD, but little is known about the associations between its components and CKD. We conducted a nationwide cross-sectional study using the updated air pollution data in the nationwide population (N = 2,938,653). Using generalized additive models, we assessed the association between long-term exposure to PM_2.5 and its components (i.e., black carbon [BC], organic matter [OM], nitrate [NO₃^-], ammonium [NH₄⁺], sulfate [SO₄^2-]), and CKD prevalence. The air pollution data was estimated using high-resolution and high-quality spatiotemporal datasets of ground-level air pollutants in China. Besides, we adopted a novel quantile-based g-computation approach to assess the effect of a mixture of PM_2.5 constituents on CKD prevalence. The average concentration of PM_2.5 was 78.67 ± 22.5 μg/m³, which far exceeded WHO AQG. In the fully adjusted generalized additive model, at a 10 km × 10 km spatial resolution, the ORs per IQR increase in previous 1-year average PM_2.5 exposures was 1.380 (95%CI: 1.345-1.415), for NH₄⁺ was 1.094 (95%CI: 1.062-1.126), for BC was 1.604 (95%CI: 1.563-1.646), for NO₃^- was 1.094 (95%CI: 1.060-1.130), for SO₄^2- was 1.239 (95%CI: 1.208-1.272), and for the OM was 1.387 (95%CI: 1.354-1.421), respectively. Subgroup analysis showed females, younger, and healthier were more vulnerable to this effect. In the further exploration of the joint effect of PM_2.5 compositions (OR 1.234 [95%CI 1.222-1.246]) per quartile increase in all 5 PM_2.5 components, we found that PM_2.5SO₄^2- contributed the most. These findings provide important evidence for the positive relationship between long-term exposure to PM_2.5 and its chemical constituents and CKD prevalence in a Chinese health check-up population, and identified PM_2.5SO₄^2- has the highest contribution to this relationship. This study provides clinical and public health guidance for reducing specific air particle exposure for those at risk of CKD.

Effect of E-Vaping on Kidney Health in Mice Consuming a High-Fat Diet

High-fat diet (HFD) consumption and tobacco smoking are risk factors for chronic kidney disease. E-cigarettes have gained significant popularity among younger populations worldwide, especially among overweight individuals. It is unclear whether vaping interacts with HFD consumption to impact renal health. In this study, Balb/c mice (male, 7 weeks old) were fed a pellet HFD (43% fat, 20 kJ/g) for 16 weeks when exposed to nicotine or nicotine-free e-vapour from weeks 11 to 16. While HFD alone increased collagen Ia and IV depositions, it did not cause significant oxidative stress and inflammatory responses in the kidney itself. On the other hand, e-vapour exposure alone increased oxidative stress and damaged DNA and mitochondrial oxidative phosphorylation complexes without significant impact on fibrotic markers. However, the combination of nicotine e-vapour and HFD increased inflammatory responses, oxidative stress-induced DNA injury, and pro-fibrotic markers, suggesting accelerated development of renal pathology. Nicotine-free e-vapour exposure and HFD consumption suppressed the production of mitochondrial OXPHOS complexes and extracellular matrix protein deposition, which may cause structural instability that can interrupt normal kidney function in the future. In conclusion, our study demonstrated that a HFD combined with e-cigarette vapour exposure, especially when containing nicotine, can increase susceptibility to kidney disease.

Associations between short-term exposure to PM2.5, NO2 and O3 pollution and kidney-related conditions and the role of temperature-adjustment specification: A case-crossover study in New York state

Epidemiologic evidence on the relationship between air pollution and kidney disease remains inconclusive. We evaluated associations between short-term exposure to PM_2.5, NO₂ and O₃ and unplanned hospital visits for seven kidney-related conditions (acute kidney failure [AKF], urolithiasis, glomerular diseases [GD], renal tubulo-interstitial diseases, chronic kidney disease, dysnatremia, and volume depletion; n = 1,209,934) in New York State (2007-2016). We applied a case-crossover design with conditional logistic regression, controlling for temperature, dew point temperature, wind speed, and solar radiation. We used a three-pollutant model at lag 0-5 days of exposure as our main model. We also assessed the influence of model adjustment using different specifications of temperature by comparing seven temperature metrics (e.g., dry-bulb temperature, heat index) and five intraday temperature measures (e.g., daily mean, daily minimum, nighttime mean), according to model performance and association magnitudes between air pollutants and kidney-related conditions. In our main models, we adjusted for daytime mean outdoor wet-bulb globe temperature, which showed good model performance across all kidney-related conditions. We observed the odds ratios (ORs) for 5 μg/m³ increase in daily mean PM_2.5 to be 1.013 (95% confidence interval [CI]: 1.001, 1.025) for AKF, 1.107 (95% CI: 1.018, 1.203) for GD, and 1.027 (95% CI: 1.015, 1.038) for volume depletion; and the OR for 5 ppb increase in daily 1-hour maximum NO₂ to be 1.014 (95% CI; 1.008, 1.021) for AKF. We observed no associations with daily 8-hour maximum O₃ exposure. Association estimates varied by adjustment for different intraday temperature measures: estimates adjusted for measures with poorer model performance resulted in the greatest deviation from estimates adjusted for daytime mean, especially for AKF and volume depletion. Our findings indicate that short-term exposure to PM_2.5 and NO₂ is a risk factor for specific kidney-related conditions and underscore the need for careful adjustment of temperature in air pollution epidemiologic studies.

Association between Air Pollution and Short-Term Outcome of ST-Segment Elevation Myocardial Infarction in a Tropical City, Kaohsiung, Taiwan

ST-segment elevation myocardial infarction (STEMI), one of the primary factors leading to global mortality, has been shown through epidemiological studies to have a relationship with short-term exposure to air pollutants; however, the association between air pollutants and the outcome of STEMI has not been well studied. The aim of this study was to estimate the impact of air pollutants on the outcomes of STEMI. Data on particulate matter <2.5 μm (PM_2.5), <10 μm (PM₁₀), nitrogen dioxide (NO₂), and ozone (O₃) at each of the 11 air monitoring stations in Kaohsiung City were collected between 1 January 2012 and 31 December 2017. Medical records of non-trauma patients aged > 20 years who had presented to the Emergency Department (ED) with a principal diagnosis of STEMI were extracted. The primary outcome measure was in-hospital mortality. After adjusting for potential confounders and meteorological variables, we found that an increase in the interquartile range (IQR) in NO₂ was associated with an elevated risk of in-hospital mortality in patients with STEMI. Moreover, there was an observed higher risk of in-hospital mortality associated with an increase in the IQR of NO₂ during the warm season, specifically in lag 3 (3 days prior to the onset, OR = 3.266; 95%CI: 1.203-8.864, p = 0.02). Conversely, an IQR increase in PM₁₀ was associated with an increased risk of in-hospital mortality in patients with STEMI in lag 3 (OR = 2.792; 95%CI: 1.115-6.993, p = 0.028) during the cold season. Our study suggests that exposure to NO₂ (during the warm season) and PM₁₀ (during the cold season) may contribute to a higher risk of poor prognosis in patients with STEMI.

Association between ambient air pollutant interaction with kidney function in a large Taiwanese population study

The associations and interactions between kidney function and other air pollutants remain poorly defined. Therefore, the aim of this study was to evaluate associations among air pollutants, including particulate matter (PM) with a diameter ≤ 2.5 μm (PM_2.5), PM₁₀ (PM with a diameter ≤ 10 μm), carbon monoxide (CO), nitrogen oxide (NO), nitrogen oxides (NO_x), sulfur dioxide (SO₂), and ozone (O₃) with kidney function, and explore interactions among these air pollutants on kidney function. We used the Taiwan Air Quality Monitoring and Taiwan Biobank databases to derive data on community-dwelling individuals in Taiwan and daily air pollution levels, respectively. We enrolled 26,032 participants. Multivariable analysis showed that high levels of PM_2.5, PM₁₀, O₃ (all p < 0.001), and SO₂ (p = 0.001) and low levels of CO, NO (both p < 0.001), and NO_x (p = 0.047) were significantly correlated with low estimated glomerular filtration rate (eGFR). With regard to negative effects, the interactions between PM_2.5 and PM₁₀ (p < 0.001), PM_2.5 and PM₁₀ (p < 0.001), PM_2.5 and SO₂, PM₁₀ and O₃ (both p = 0.025), PM₁₀ and SO₂ (p = 0.001), and O₃ and SO₂ (p < 0.001) on eGFR were significantly negatively. High PM₁₀, PM_2.5, O₃, and SO₂ were associated with a low eGFR, whereas high CO, NO, and NO_x were associated with a high eGFR. Furthermore, negative interactions between PM_2.5 and PM₁₀, O₃ and SO₂, PM₁₀ and O₃, PM_2.5 and SO₂, and PM₁₀ and SO₂ on eGFR were observed. The findings of this study have important implications for public health and environmental policy. Specifically, the results of this study may be useful in individuals and organizations to take action to reduce air pollution and promote public health.

Vitamin B ameliorates PM2.5-induced kidney damage by reducing endoplasmic reticulum stress and oxidative stress in pregnant mice and HK-2

As an air pollutant, particulate matters 2.5 (PM_2.5) poses a severe risk to kidney and the mechanism involves oxidative stress and endoplasmic reticulum (ER) stress. As an essential nutrient for human health, Vitamin B performs anti-inflammatory and antioxidant functions. In order to study the effect of Vitamin B on PM_2.5-induced kidney damage during pregnancy, the pregnant mice were divided into the four experimental groups randomly: control group, model group, treatment group and VB group. PM_2.5 was sprayed on the trachea of pregnant mice once each three days for six times from pregnancy until delivery. The model group was given 30μL PM_2.5 suspension of 3.456μg/μL and 10mL/(kg·d) PBS. The treatment group was given 30μL PM_2.5 suspension of 3.456μg/μL and 10mL/(kg·d) Vitamin B. The VB group was given 10mL/(kg·d) Vitamin B and the control group was given the same dose of PBS. Vitamin B was composed of Vitamin B6, Vitamin B12 and folic acid, with final concentrations are 1.14, 0.02 and 0.06mg/mL, respectively. The results showed Vitamin B ameliorated PM_2.5-induced kidney damage such as improving histopathological change, decreasing expressions of Bip and Chop, increasing expressions of Nrf2, HO-1 and Nqo1. In addition, HK-2 cells were used for cell experiments and were divided into the four groups, in which the dosage of PM_2.5 was 75μg/mL for 24h and Vitamin B was 5μL/100μL. The results showed Vitamin B ameliorated PM_2.5-induced HK-2 damage, such as decreasing expressions of Bip, Chop, P47^phox and ROS, increasing expressions of Nrf2, HO-1, Nqo1 and NO. Our findings showed Vitamin B ameliorated PM_2.5-induced kidney damage by reducing ER stress and oxidative stress in pregnant mice and in HK-2.

Toxicological Effects of Fine Particulate Matter (PM2.5): Health Risks and Associated Systemic Injuries-Systematic Review

Previous studies focused on investigating particulate matter with aerodynamic diameter ≤ 2.5 µm (PM2.5) have shown the risk of disease development, and association with increased morbidity and mortality rates. The current review investigate epidemiological and experimental findings from 2016 to 2021, which enabled the systemic overview of PM2.5's toxic impacts on human health. The Web of Science database search used descriptive terms to investigate the interaction among PM2.5 exposure, systemic effects, and COVID-19 disease. Analyzed studies have indicated that cardiovascular and respiratory systems have been extensively investigated and indicated as the main air pollution targets. Nevertheless, PM2.5 reaches other organic systems and harms the renal, neurological, gastrointestinal, and reproductive systems. Pathologies onset and/or get worse due to toxicological effects associated with the exposure to this particle type, since it can trigger several reactions, such as inflammatory responses, oxidative stress generation and genotoxicity. These cellular dysfunctions lead to organ malfunctions, as shown in the current review. In addition, the correlation between COVID-19/Sars-CoV-2 and PM2.5 exposure was also assessed to help better understand the role of atmospheric pollution in the pathophysiology of this disease. Despite the significant number of studies about PM2.5's effects on organic functions, available in the literature, there are still gaps in knowledge about how this particulate matter can hinder human health. The current review aimed to approach the main findings about the effect of PM2.5 exposure on different systems, and demonstrate the likely interaction of COVID-19/Sars-CoV-2 and PM2.5.

Combined effects of ambient air pollution and PM2.5 components on renal function and the potential mediation effects of metabolic risk factors in China

Growing evidence links long-term air pollution exposure with renal function. However, little research has been conducted on the combined effects of air pollutant mixture on renal function and multiple mediation effects of metabolic risk factors. This study enrolled 8996 adults without chronic kidney disease (CKD) at baseline from the CHCN-BTH cohort study. Three-year exposure to air pollutants [particulate matter ≤ 2.5 µm (PM_2.5), PM₁₀, PM₁, ozone (O₃), nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and carbon monoxide (CO)] and PM_2.5 components [black carbon (BC), ammonium (NH₄⁺), nitrate (NO₃^-), sulfate (SO₄^2-) and organic matter (OM)] were assessed using well-validated machine learning methods. Linear mixed models were applied to investigate the associations between air pollutants and estimated glomerular filtration rate (eGFR). Quantile G-computation was used to assess the combined effects of pollutant mixtures. Causal mediation analysis and Bayesian mediation analysis were employed to estimate the mediation effects of metabolic risk factors. An interquartile range increases in BC (-0.256, 95 %CI: -0.331, -0.180) and OM (-0.603, 95 %CI: -0.810, -0.397) were significantly associated with eGFR decline; while O₃ (1.151, 95 %CI: 0.813, 1.489), PM₁₀ (0.721, 95 %CI: 0.309, 1.133), NH₄⁺ (0.990, 95 %CI: 0.638, 1.342), and NO₃^- (0.610, 95 %CI: 0.405, 0.815) were associated with higher eGFR. The combined effect of the PM_2.5 component mixture was found to be associated with lower eGFR (-1.147, 95 % CI: -1.456, -0.839), with OM contributing 72.4 % of the negative effect. Univariate mediation analyses showed that high-density lipoprotein (HDL) mediated 7.1 %, 6.9 %, and 6.1 % effects of O₃, BC, and OM, respectively. However, these mediation effects were not significant in Bayesian mediation analysis. These findings suggest the effect of the PM_2.5 component mixture on eGFR decline and the strong contribution of OM. Metabolic risk factors may not mediate the effects of air pollutants. Further study is warranted to clarify the potential mechanisms involved.

Overview of PM2.5 and health outcomes: Focusing on components, sources, and pollutant mixture co-exposure

PM_2.5 varies in source and composition over time and space as a complicated mixture. Consequently, the health effects caused by PM_2.5 varies significantly over time and generally exhibit significant regional variations. According to numerous studies, a notable relationship exists between PM_2.5 and the occurrence of many diseases, such as respiratory, cardiovascular, and nervous system diseases, as well as cancer. Therefore, a comprehensive understanding of the effect of PM_2.5 on human health is critical. The toxic effects of various PM_2.5 components, as well as the overall toxicity of PM_2.5 are discussed in this review to provide a foundation for precise PM_2.5 emission control. Furthermore, this review summarizes the synergistic effect of PM_2.5 and other pollutants, which can be used to draft effective policies.

Subchronic co-exposure to particulate matter and fructose-rich-diet induces insulin resistance in male Sprague Dawley rats

Insulin resistance (IR) and metabolic disorders are non-pulmonary adverse effects induced by fine particulate matter (PM_2.5) exposure. The worldwide pandemic of high fructose sweeteners and fat rich modern diets, also contribute to IR development. We investigated some of the underlying effects of IR, altered biochemical insulin action and Insulin/AKT pathway biomarkers. Male Sprague Dawley rats were subchronically exposed to filtered air, PM_2.5, a fructose rich diet (FRD), or PM_2.5 + FRD. Exposure to PM_2.5 or FRD alone did not induce metabolic changes. However, PM_2.5 + FRD induced leptin release, systemic hyperinsulinemia, and Insulin/AKT dysregulation in insulin-sensitive tissues preceded by altered AT₁R levels. Histological damage and increased HOMA-IR were also observed from PM_2.5 + FRD co-exposure. Our results indicate that the concomitant exposure to a ubiquitous environmental pollutant, such as PM_2.5, and a metabolic disease risk factor, a FRD, can contribute to the metabolic disorder pandemic occurring in highly polluted locations.

Biomonitoring of unmetabolized polycyclic aromatic hydrocarbons (PAHs) in urine of waterpipe/cigarette café workers

Fresh tobacco or the smoke resulting from waterpipe and cigarette contains large amounts of polycyclic aromatic hydrocarbons (PAHs), which consumption can cause releasing of these contaminants into the indoor air of cigarette and waterpipe cafés. This study was conducted to investigate the urinary concentrations of unmetabolized PAH compounds among the employed workers as well as the customers in waterpipe and cigarette cafés along with its association with oxidative stress factors plus kidney injury biomarkers. For this, 35 staffs and 35 customers in these cafés (as an exposed group (EG)), 20 staffs in non-smoking cafés (as 1st control group (CG-1)), and 20 of the public population (as 2nd control group 2 (CG-2)) were chosen and their urine specimens were collected. The results indicated that there is a significant difference between urinary concentration of ƩPAHs in the exposed and control groups (P value < 0.05). Also, "type of tobacco" can be considered as an influential and determining factor for the urinary levels of PAHs among the subjects. Considering the contribution of PAHs to the total toxic equivalents, benzo[a]pyrene (BaP), dibenzo[a,h]anthracene (DahA), and fluoranthene (Flrt) with 32.76%, 27.62%, and 18.65% claimed the largest share in waterpipe/cigarette cafés. The results also indicated a positive and significant relationship between some PAHs and oxidative stress biomarkers as well as uKIM-1 (biomarker for assessing and diagnosing glomerular damage) and TIMP-1 (biomarker of stress in primary steps of injury in tubular cell). Thus, it can be expressed that the workers of these smoking cafés are prone to the detrimental health impacts. Accordingly, proper policies and decisions should be taken to limit the activity of these cafés or proper protective strategies should be adopted to protect the health of exposed individuals.

Mining biomarkers from routine laboratory tests in clinical records associated with air pollution health risk assessment

Clinical laboratory in hospital can produce amounts of health data every day. The purpose of this study was to mine biomarkers from clinical laboratory big data associated with the air pollution health risk assessment using clinical records. 13, 045, 629 clinical records of all 27 routine laboratory tests in Changsha Central Hospital, including ALB, TBIL, ALT, DBIL, AST, TP, UREA, UA, CREA, GLU, CK, CKMB, LDL-C, TG, TC, HDL-C, CRP, WBC, Na, K, Ca, Cl, APTT, PT, FIB, TT, RBC and those daily air pollutants concentration monitoring data of Changsha, including PM_2.5, PM₁₀, SO₂, NO₂, CO, and O₃ from 2014 to 2016, were retrieved. The moving average method was used to the biological reference interval was established. The tests results were converted into daily abnormal rate. After data cleaning, GAM statistical model construction and data analysis, a concentration-response relationship between air pollutants and daily abnormal rate of routine laboratory tests was observed. Our study found that PM_2.5 had a stable association with TP (lag07), ALB (lag07), ALT (lag07), AST (lag07), TBIL (lag07), DBIL (lag07), UREA (lag07), CREA (lag07), UA (lag07), CK (lag 06), GLU (lag07), WBC (lag07), Cl (lag07) and Ca (lag07), (P < 0.05); O₃ had a stable association with AST (lag01), CKMB (lag06), TG (lag07), TC (lag05), HDL-C (lag07), K (lag05) and RBC (lag07) (P < 0.05); CO had a stable association with UREA (lag07), Na (lag7) and PT (lag07) (P < 0.05); SO₂ had a stable association with TP (lag07) and LDL-C (lag0) (P < 0.05); NO₂ had a stable association with APTT (lag7) (P < 0.05). These results showed that different air pollutants affected different routine laboratory tests and presented different pedigrees. Therefore, biomarkers mined from routine laboratory tests may potentially be used to low-cost assess the health risks associated with air pollutants.

The impact of PM2.5 on kidney

PM2.5 poses a severe risk to kidneys, inducing kidney function decline, increasing the risk of suffering from chronic kidney diseases and promoting the occurrence and development of various renal tumors. The mechanism of PM2.5-induced renal injury may involve oxidative stress, inflammatory response, and cytotoxicity. This paper elaborated PM2.5-induced kidney damage and the corresponding possible mechanism so as to raise awareness of air pollution and reduce the damage to human body.

Urinary profile of PAHs and related compounds in women working in beauty salons

Polycyclic aromatic hydrocarbons (PAHs) are a group of chemical compounds which interest to human biological monitoring researches because of their potential carcinogenic, mutagenic, and teratogenic properties. However, the exposure of female beauticians to these contaminants is not well-reported. For biomonitoring of potential exposure of female cosmeticians to PAHs in beauty salons, urine samples were taken from cosmetologist women (n = 50.00) and housewives (n = 35.00) as the exposure group (EG) and control group (CG), respectively. Next, unmetabolized PAHs levels as well as the concentration of - 1-hydroxypyrene (1-OHP) were analyzed in these specimens. In addition, since benzene has some common source with PAHs, in this study t, t'-Muconic acid (TTMA) level was also determined as the metabolite and indicator of exposure to benzene. The results indicated a high detection frequency of the target compounds (PAHs, 1-OHP and TTMA) in the urine specimens of beauticians. The results also showed that there is a significant difference between the concentration of these pollutants in the urine specimens of the exposure and control groups. The median concentration of ΣPAHs, 1-OHP, and TTMA in the before exposure (BE) specimens collected from the exposure group were 337.42 ng/L, 593.92 ng/L, and 247.90 μg/L, respectively. However, a higher concentration of these contaminants was observed in the after exposure specimens with a median concentration of 423.29 ng/L, 745.03 ng/L, and 310.97 μg/L, respectively. In terms of contribution of PAHs compounds in total toxic equivalents, DahA, BaP, and IndP with 59.03, 28.73, and 2.86 % had the largest share. In this study, it was also observed that some kidney damage biomarkers as well as some oxidative stress injury biomarkers are positively and significantly correlated with the urinary values of ∑PAHs. Thus, it can be concluded that high health risks threaten the female beauticians regarding kidney injury and DNA oxidative stress.

Exposure to ambient air pollutants with kidney function decline in chronic kidney disease patients

Chronic kidney disease (CKD) has been a global public health problem with many adverse outcomes, but data are lacking regarding the relationship between air pollutants and risk of renal progression in patients with CKD. This study was to investigate whether 1-year average exposure to ambient air pollutants -CO, NO, NO₂, SO₂, O₃, PM_2.5, and PM₁₀-is related to renal function deterioration among patients with CKD. A total of 5301 CKD patients were included in this study between October 2008 and February 2016. To estimate each patient's exposure to ambient air pollution, we used the 24-h ambient air pollution concentration monitoring data collected one year prior to renal progression or their last renal function assessment. Renal progression was considered when estimated glomerular filtration rate (eGFR) decreased more than 25% from the baseline eGFR. Cox proportional hazard regression was performed to calculate hazard ratios (HRs). Among 5301 patients with CKD, 1813 (34.20%) developed renal progression during the 30.48 ± 14.99-month follow-up. Patients with the highest quartile exposure to CO [HR = 1.53 (95% CI: 1.24, 1.88)], NO [HR = 1.38 (95% CI: 1.11, 1.71)], NO₂ [HR = 1.63 (95% CI: 1.36, 1.97)], SO₂ [HR = 2.27 (95% CI: 1.83, 2.82)], PM_2.5 [HR = 7.58 (95% CI: 5.97, 9.62)], and PM₁₀ [HR = 3.68 (95% CI: 2.84, 4.78)] had a significantly higher risk of renal progression than those with the lowest quartile exposure. In the multipollutant model, the analyses yielded to similar results. These results reinforce the importance of measures to mitigate air pollution and strategies to prevent worsening of kidney function in patients with CKD. One-year high exposure to ambient CO, NO, NO₂, SO₂, PM_2.5, and PM₁₀ is significantly associated with deteriorated kidney function in patients with CKD among Taiwanese adults.

Kidney damage induced by repeated fine particulate matter exposure: Effects of different components

BACKGROUND

Exposure to fine particulate matter with an aerodynamic diameter of ≤2.5 μm (PM_2.5) is associated with adverse health effects. This study aimed to evaluate the toxic effects of the constituents of PM_2.5 on mouse kidneys.

METHODS

We collected PM_2.5 near an industrial complex located in southern Kaohsiung, Taiwan, that was divided into water extract and insoluble particles. Male C57BL/6 mice were divided into five groups: control, low- and high-dose insoluble particle exposure, and low- and high-dose water extract exposure. Biochemical analysis, Western blot analysis, histological examination, and immunohistochemistry were performed to evaluate the impact of PM_2.5 constituents on mice kidneys.

RESULTS

PM_2.5 was collected from January 1, 2021, to February 8, 2021, from an industrial complex in Kaohsiung, Taiwan. Metallic element analysis showed that Pb, Ni, V, and Ti were non-essential metals with enrichment factors >10. Polycyclic aromatic hydrocarbon and nitrate polycyclic aromatic hydrocarbon analyses revealed that the toxic equivalents are, in the order, benzo(a)pyrene (BaP), indeno(1,2,3-cd) pyrene (IP), dibenzo(a,h)anthracene (DBA), and benzo(b)fluoranthene (BbF), which are potential carcinogens. Both water extract and insoluble particle exposure induced inflammatory cytokine upregulation, inflammatory cell infiltration, antioxidant activity downregulation, and elevation of kidney injury molecule 1 (KIM-1) level in mouse kidneys. A dose-dependent effect of PM_2.5 water extract and insoluble particle exposure on angiotensin converter enzyme 2 downregulation in mouse kidneys was observed.

CONCLUSION

We found that water-soluble extract and insoluble particles of PM_2.5 could induce oxidative stress and inflammatory reactions, influence the regulation of renin-angiotensin system (RAS), and lead to kidney injury marker level elevation in mouse kidneys. The lowest-observed-adverse-effect level for renal toxicity in mice was 40 μg water-soluble extract/insoluble particle inhalation per week, which was approximately equal to the ambient PM_2.5 concentration of 44 μg/m³ for mice.

Association of Long-term Ambient Fine Particulate Matter (PM2.5) and Incident CKD: A Prospective Cohort Study in China

RATIONALE & OBJECTIVE

Increasing evidence has linked ambient fine particulate matter (ie, particulate matter no larger than 2.5 μm [PM_2.5]) to chronic kidney disease (CKD), but their association has not been fully elucidated, especially in regions with high levels of PM_2.5 pollution. This study aimed to investigate the long-term association of high PM_2.5 exposure with incident CKD in mainland China.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

72,425 participants (age ≥18 years) without CKD were recruited from 121 counties in Hunan Province, China.

EXPOSURE

Annual mean PM_2.5 concentration at the residence of each participant derived from a long-term, full-coverage, high-resolution (1 × 1 km²), high-quality dataset of ground-level air pollutants in China.

OUTCOMES

Incident CKD during the interval between the baseline examination of each participant (2005-2017) and the end of follow-up through 2018.

ANALYTICAL APPROACH

Cox proportional hazards models were used to estimate the independent association of PM_2.5 with incident CKD and the joint association of PM_2.5 with temperature or humidity on the development of PM_2.5-related CKD. Restricted cubic splines were used to model exposure-response relationships.

RESULTS

Over a median follow-up of 3.79 (IQR, 2.03-5.48) years, a total of 2,188 participants with incident CKD were identified. PM_2.5 exposure was associated with incident CKD with an adjusted hazard ratio of 1.71 (95% CI, 1.58-1.85) per 10-μg/m³ greater long-term exposure. Multiplicative interactions between PM_2.5 and humidity or temperature on incident CKD were detected (all P < 0.001 for interaction), whereas an additive interaction was detected only for humidity (relative risk due to interaction, 3.59 [95% CI, 0.97-6.21]).

LIMITATIONS

Lack of information on participants' activity patterns such as time spent outdoors.

CONCLUSIONS

Greater long-term ambient PM_2.5 pollution is associated with incident CKD in environments with high PM_2.5 exposure. Ambient humidity has a potentially synergetic effect on the association of PM_2.5 with the development of CKD.

PLAIN-LANGUAGE SUMMARY

Exposure to a form of air pollution known as fine particulate matter (ie, particulate matter ≤2.5 μm [PM_2.5]) has been linked to an increased risk of chronic kidney disease (CKD), but little is known about how PM_2.5 affects CKD in regions with extremely high levels of PM_2.5 pollution. This longitudinal cohort study in China investigates the effect of PM_2.5 on the incidence of CKD and whether temperature or humidity interact with PM_2.5. Our findings suggest that long-term exposure to high levels of ambient PM_2.5 significantly increased the risk of CKD in mainland China, especially in terms of cumulative average PM_2.5. The associations of PM_2.5 and incident CKD were greater in high-humidity environments. These findings support the recommendation that reducing PM_2.5 pollution should be a priority to decrease the burden of associated health risks, including CKD.

Effects of air pollution on human health - Mechanistic evidence suggested by in vitro and in vivo modelling

Airborne particulate matter (PM) comprises both solid and liquid particles, including carbon, sulphates, nitrate, and toxic heavy metals, which can induce oxidative stress and inflammation after inhalation. These changes occur both in the lung and systemically, due to the ability of the small-sized PM (i.e. diameters ≤2.5 μm, PM_2.5) to enter and circulate in the bloodstream. As such, in 2016, airborne PM caused ∼4.2 million premature deaths worldwide. Acute exposure to high levels of airborne PM (eg. during wildfires) can exacerbate pre-existing illnesses leading to hospitalisation, such as in those with asthma and coronary heart disease. Prolonged exposure to PM can increase the risk of non-communicable chronic diseases affecting the brain, lung, heart, liver, and kidney, although the latter is less well studied. Given the breadth of potential disease, it is critical to understand the mechanisms underlying airborne PM exposure-induced disorders. Establishing aetiology in humans is difficult, therefore, in-vitro and in-vivo studies can provide mechanistic insights. We describe acute health effects (e.g. exacerbations of asthma) and long term health effects such as the induction of chronic inflammatory lung disease, and effects outside the lung (e.g. liver and renal change). We will focus on oxidative stress and inflammation as this is the common mechanism of PM-induced disease, which may be used to develop effective treatments to mitigate the adverse health effect of PM exposure.

Multiple pathways and mediation effects of built environment on kidney disease rate via mitigation of atmospheric threats

Air pollution and high temperatures can increase kidney disease rate, especially under climate change. A well-designed urban environment has mediating effects on atmospheric environmental threats and promoting human health, but previous studies have overlooked these effects. This study used partial least squares modeling and urban-scale data from Taiwan to identify the crucial effects (i.e., direct, indirect, and total effects) and pathways of urban form (i.e., urban development intensity, land-use mix, and urban sprawl), urban greening (i.e., green coverage), urban industrial status (e.g., industrial level), atmospheric environment (i.e., high temperature and air pollution), and socioeconomic status (i.e., elderly ratio, medical resources, and economic status) on kidney disease rate. Maximizing land-use mix and green coverage and minimizing urban development intensity, urban sprawl, and industrial levels could help reduce kidney disease rate. Air pollution and high temperature had a mediation effect of built environment on kidney disease rate; with the mediation effect of air pollution was greater than that of high temperature. Furthermore, air pollution, high temperature, and elderly ratio increased kidney disease rate, whereas medical resources decreased kidney disease rate. This study is the first to consider the impact (i.e., direct, indirect, and total effects) and pathways of built environment characteristics on kidney disease rate. The findings revealed that an appropriate urban policy might be a practical strategy and lower kidney disease rate for a healthy city development. Moreover, this study provides a new approach for clarifying complex relationships and identifying crucial factors.

Exposure to airborne particulate matter induces renal tubular cell injury in vitro: the role of vitamin D signaling and renin-angiotensin system

Background

Exposure to air pollution can interfere with the vitamin D endocrine system. This study investigated the effects of airborne particulate matter (PM) on renal tubular cell injury in vitro and explored the underlying mechanisms.

Methods

HK-2 human renal proximal tubule cells were treated with PM with or without 1,25(OH)₂D₃ analog, 19-Nor-1,25(OH)₂D₂ (paricalcitol, 10 nM) for 48 h. The dose- and time-dependent cytotoxicity of PM with or without paricalcitol was determined via cell counting kit-8 assay. Cellular oxidative stress was assessed using commercially available enzyme-linked immunosorbent assay kits. The protein expression of vitamin D receptor (VDR), cytochrome P450(CYP)27B1, CYP24A1, renin, angiotensin converting enzyme (ACE), angiotensin II type 1 receptor (AT1), nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor-kB (NF-kB), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 was determined.

Results

PM exposure decreased HK-2 cell viability in a dose- and time-dependent manner. The activities of superoxide dismutase and malondialdehyde in HK-2 cells increased significantly in the group exposed to PM. PM exposure decreased VDR and Nrf2, while increasing CYP27B1, renin, ACE, AT1, NF-kB, TNF-α, and IL-6. The expression of VDR, CYP27B1, renin, ACE, AT1, and TNF-α was reversed by paricalcitol treatment. Paricalcitol also restored the cell viability of PM-exposed HK-2 cells.

Conclusion

Our findings indicate that exposure to PM induces renal proximal tubular cell injury, concomitant with alteration of vitamin D endocrine system and renin angiotensin system. Vitamin D could attenuate renal tubular cell damage following PM exposure by suppressing the renin-angiotensin system and by partially inhibiting the inflammatory response.

The Physiological Effects of Air Pollution: Particulate Matter, Physiology and Disease

Nine out of 10 people breathe air that does not meet World Health Organization pollution limits. Air pollutants include gasses and particulate matter and collectively are responsible for ~8 million annual deaths. Particulate matter is the most dangerous form of air pollution, causing inflammatory and oxidative tissue damage. A deeper understanding of the physiological effects of particulate matter is needed for effective disease prevention and treatment. This review will summarize the impact of particulate matter on physiological systems, and where possible will refer to apposite epidemiological and toxicological studies. By discussing a broad cross-section of available data, we hope this review appeals to a wide readership and provides some insight on the impacts of particulate matter on human health.

Association between gaseous air pollutants and idiopathic nephrotic syndrome in children: a 12-year population-based cohort study

Background

To date, there is insufficient knowledge about the association of air pollution and childhood nephrotic syndrome in the real world. This study aimed to evaluate the effects of the three common gaseous air pollutants, including sulfur dioxide, total hydrocarbon, and methane, on the risk of idiopathic nephrotic syndrome (INS) in children.

Methods

We collected data from the Taiwan National Health Insurance Research Database and Taiwan Air Quality-Monitoring Database. Children younger than 18 years old, identified from January 1, 2000, were followed up until the first diagnosis of INS was established or until December 31, 2012. We measured the incidence rates and hazard ratios for INS stratified based on the quartiles (Q1–Q4) of air pollutant concentration. Multivariate Cox proportional hazards models were also applied by adjusting age, sex, monthly income, and urbanization.

Results

Compared with participants exposed to Q1 concentrations, the adjusted hazard ratios (aHRs) for INS increased progressively along the four quartiles of sulfur dioxide, total hydrocarbon, and methane, from 1 (Q1) to 1.78 (Q4), 1 (Q1) to 3.49 (Q4), 1 (Q1) to 7.83 (Q4), respectively.

Conclusions

Our study revealed that children with exposure to higher concentrations of sulfur dioxide, total hydrocarbon, and methane was associated with an increased risk of INS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-022-01269-8.

Short-term exposure to fine particulate matter and its constituents may affect renal function via oxidative stress: A longitudinal panel study

Exposure to fine particulate matter (PM_2.5) has been reported to increase the risks of chronic kidney disease. However, limited research has assessed the effect of PM_2.5 and its constituents on renal function, and the underlying mechanism has not been well characterized. We aimed to evaluate the association of PM_2.5 and its constituents with kidney indicators and to explore the roles of systematic oxidative stress and inflammation in the association. We conducted a longitudinal panel study among 35 healthy adults before-, intra- and after-the 2019 Wuhan Military World Games. We repeatedly measured 6 renal function parameters and 5 circulating biomarkers of oxidative stress and inflammation at 6 rounds of follow-ups. We monitored hourly personal PM_2.5 concentrations with 3 consecutive days and measured 10 metals (metalloids) and 16 polycyclic aromatic hydrocarbons (PAHs) components. The linear mixed-effect models were applied to examine the association between PM_2.5 and renal function parameters, and the mediation analysis was performed to explore potential bio-pathways. PM_2.5 concentrations across Wuhan showed a slight decrease during the Military Games. We observed significant associations between elevated blood urea nitrogen (BUN) levels and PM_2.5 and its several metals and PAHs components. For an interquartile range (IQR) increase of PM_2.5, BUN increased 0.42 mmol/L (95% CI: 0.14 to 0.69). On average, an IQR higher of lead (Pb), cadmium (Cd), arsenic (As), selenium (Se), thallium (Tl) and Indeno (1,2,3-cd) pyrene (IPY) were associated with 0.90, 0.65, 0.29, 0.27, 0.26 and 0.90 mmol/L increment of BUN, respectively. Moreover, superoxide dismutase was positively associated with PM_2.5 and mediated 18.24% association. Our research indicated that exposure to PM_2.5 might affect renal function by activating oxidative stress pathways, in which the constituents of Pb, Cd, As, Se, Tl and IPY might contribute to the associations.

The influence of PM2.5 exposure on kidney diseases

The harm of air pollution to public health has become a research hotspot, especially atmospheric fine-particulate matter (PM_2.5). In recent years, epidemiological investigations have confirmed that PM_2.5 is closely related to chronic kidney disease and membranous nephropathy Basic research has demonstrated that PM_2.5 has an impact on the normal function of the kidneys through accumulation in the kidney, endothelial dysfunction, abnormal renin-angiotensin system, and immune complex deposition. Moreover, the mechanism of PM_2.5 damage to the kidney involves inflammation, oxidative stress, apoptosis, DNA damage, and autophagy. In this review, we summarized the latest developments in the effects of PM_2.5 on kidney disease in human and animal studies, so as to provide new ideas for the prevention and treatment of kidney disease.

The biomechanistic aspects of renal cortical injury induced by diesel exhaust particles in rats and the renoprotective contribution of quercetin pretreatment: Histological and biochemical study

Although several studies have reported a toxic effect of diesel exhaust particles (DEP) exposure on the kidney tissues, the involvement of autophagy/NF-kB signaling as encountered mechanisms and the protective effects of a natural flavonoid, quercetin on DEP remains unclear. Thirty-two albino rats were divided as control, quercetin-treated (60 mg/kg, oral), DEP-exposed (0.5 mg/kg, intra-tracheal), and quercetin/DEP-exposed groups. Specimens of the renal cortex were subjected to histo-biochemical study and immunohistochemical analysis using anti-NF-kB, and anti-LC3β antibodies followed by morphometric and statistical analyses. The expression level of autophagy genes was quantitatively evaluated using RT-PCR, as well. The DEP-exposed rats showed an elevation in the renal tissue levels of MDA and a decrease in the catalase and superoxide dismutase (p < .05). Histologically, there were cytoplasmic vacuolar changes in the lining cells of the renal tubules, glomerular atrophy, and vascular congestion. In addition, renal inflammation was evident as confirmed by the increased NF-kB immunoexpression. Moreover, the gene expression of Becn1, ATG5, and LC3β increased (p <. 0) due to DEP exposure. Conversely, quercetin pretreatment improved these renal histo-biochemical alterations (p < .05) and regulated autophagy/NF-kB pathways. Overall, the study proved the renal toxicity mediated by DEP exposure via precipitating renal inflammation, autophagy activation, and oxidative stress. Quercetin pretreatment could antagonize such machinery to protect the kidney against DEP.

Biomarkers for the adverse effects on respiratory system health associated with atmospheric particulate matter exposure

Large amounts of epidemiological evidence have confirmed the atmospheric particulate matter (PM_2.5) exposure was positively correlated with the morbidity and mortality of respiratory diseases. Nevertheless, its pathogenesis remains incompletely understood, probably resulting from the activation of oxidative stress, inflammation, altered genetic and epigenetic modifications in the lung upon PM_2.5 exposure. Currently, biomarker investigations have been widely used in epidemiological and toxicological studies, which may help in understanding the biologic mechanisms underlying PM_2.5-elicited adverse health outcomes. Here, the emerging biomarkers to indicate PM_2.5-respiratory system interactions were summarized, primarily related to oxidative stress (ROS, MDA, GSH, etc.), inflammation (Interleukins, FE_NO, CC16, etc.), DNA damage (8-OHdG, γH2AX, OGG1) and also epigenetic modulation (DNA methylation, histone modification, microRNAs). The identified biomarkers shed light on PM_2.5-elicited inflammation, fibrogenesis and carcinogenesis, thus may favor more precise interventions in public health. It is worth noting that some inconsistent findings may possibly relate to the inter-study differentials in the airborne PM_2.5 sample, exposure mode and targeted subjects, as well as methodological issues. Further research, particularly by -omics technique to identify novel, specific biomarkers, is warranted to illuminate the causal relationship between PM_2.5 pollution and deleterious lung outcomes.

Associations of Carbonaceous Compounds and Water-Soluble Inorganic Ions in Ambient PM2.5 with Renal Function in Older Individuals: The China BAPE Study

Exposure to fine particulate matter (PM_2.5) is proven to be associated with a decline in renal function. However, few studies have explored the acute renal damage from carbonaceous compounds and water-soluble inorganic ions (WSIIs), which constitute the bulk of total PM_2.5 mass. We examined the acute effect of these constituents of ambient PM_2.5 on renal function in older Chinese individuals. Seventy-one healthy people aged 60-69 years from Jinan, China, were enrolled and visited monthly and asked to complete survey questionnaires, undergo physical exams, and provide blood samples. The hourly concentrations of organic carbon, elemental carbon (EC), and WSIIs in ambient PM_2.5 were collected from a fixed-site monitoring station. The association between PM_2.5 constituents and estimated glomerular filtration rate (eGFR) was evaluated using linear mixed-effects models after controlling for a series of covariates. We observed that ambient carbonaceous compounds and WSIIs were associated with a significant decline in renal function. The interquartile range increased in the 24 h moving average of carbonaceous compounds, and WSIIs in ambient PM_2.5 were associated with -13.11% [95% confidence interval (95% CI): -19.49, -6.21%] to -0.81% (95% CI: -4.17, 2.67%) changes in eGFR. We found significant associations between EC, chlorine (Cl^-), sodium (Na⁺), and magnesium (Mg²⁺) and eGFR in single-pollutant, constituent-PM_2.5, and residual-constituent models with a lag period of 0-24 h. This study demonstrated that carbonaceous compounds and WSIIs in PM_2.5 were inversely associated with renal function.

MicroRNAs: Potential mediators between particulate matter 2.5 and Th17/Treg immune disorder in primary membranous nephropathy

Primary membranous nephropathy (PMN), is an autoimmune glomerular disease and the main reason of nephrotic syndrome in adults. Studies have confirmed that the incidence of PMN increases yearly and is related to fine air pollutants particulate matter 2.5 (PM2.5) exposure. These imply that PM2.5 may be associated with exposure to PMN-specific autoantigens, such as the M-type receptor for secretory phospholipase A2 (PLA2R1). Emerging evidence indicates that Th17/Treg turns to imbalance under PM2.5 exposure, but the molecular mechanism of this process in PMN has not been elucidated. As an important indicator of immune activity in multiple diseases, Th17/Treg immune balance is sensitive to antigens and cellular microenvironment changes. These immune pathways play an essential role in the disease progression of PMN. Also, microRNAs (miRNAs) are susceptible to external environmental stimulation and play link role between the environment and immunity. The contribution of PM2.5 to PMN may induce Th17/Treg imbalance through miRNAs and then produce epigenetic affection. We summarize the pathways by which PM2.5 interferes with Th17/Treg immune balance and attempt to explore the intermediary roles of miRNAs, with a particular focus on the changes in PMN. Meanwhile, the mechanism of PM2.5 promoting PLA2R1 exposure is discussed. This review aims to clarify the potential mechanism of PM2.5 on the pathogenesis and progression of PMN and provide new insights for the prevention and treatment of the disease.

OUP accepted manuscript

Air pollution is an emerging etiology of chronic kidney disease (CKD). Evidence regarding this causative relationship has been shown by several studies. Recently, Lin et al. conducted the first community-based study investigating the association between CKD prevalence and air pollutant levels utilizing a Fuzzy Logic Interference model. Despite the study's limitations, the results correlate with the previous meta-analysis and observational studies. Higher fine particular matter (PM2.5) levels are associated with the increased global burden of CKD and may also influence the unequal distribution of burden in low-to-middle income countries. Despite growing evidence of the association of air pollution with CKD risk, the underlying pathophysiology has yet to be fully understood. Future studies investigating the pathophysiology and efficiency of the potential therapeutic and preventive measures against air pollution-related kidney injury are required to reduce the CKD burden.

Association of meteorological factors and ambient air pollution on medical care utilization for urolithiasis: a population-based time-series study

BACKGROUND

To identify the association of meteorological factors/ambient air pollutants with medical care utilization for urolithiasis and estimate the effect size/time lags.

METHODS

This is a population-based time-series analysis of 300,000 urolithiasis cases from eight large metropolitan areas in Korea. Seventeen meteorological factors and ambient air pollutants were measured daily during 2002-2017 for each metropolis. Data on daily medical utilization owing to urolithiasis were collected. A generalized additive model was used while factoring in the nonlinear relationship between meteorological factors/ambient air pollutants and urolithiasis and a time lag of ≤10 days. A multivariate analysis was performed. Backward elimination with an Akaike information criterion was used for fitting the multivariate model.

RESULTS

Urolithiasis was significantly associated with average temperature, diurnal temperature range, sunshine duration, particulate matter (PM) ≤2.5 μm, and carbon monoxide (CO) levels. The incidence of ureteral stones was positively correlated with average temperature, PM ≤2.5 μm level, and CO level (time lags 0-9, 2-4, and 0-9 days, respectively). The incidence of renal stones was positively correlated with PM ≤2.5 μm and CO levels (time lags 2-4 and 0-9 days, respectively). PM ≤2.5 μm (0.05 and 0.07% per 10 μg/m³⁾ and CO (2.05 and 2.25% per 0.1 ppm) conferred the highest excess risk on ureteral and renal stones.

CONCLUSIONS

Urolithiasis is affected by various meteorological factors and ambient air pollutants, PM ≤2.5 μm, and CO levels may be novel potential risk factors for this condition.

Ambient particulate matter levels and health profile in residents of Choba and Mgbuoba areas of Rivers State: A cross-sectional study

The study investigated the health profile of individuals exposed to particulate matter (Black) soot in Choba and Mgbuoba localities of Port Harcourt. The analysis was executed with the aid of 100 respondents (50 from Choba and 50 from Mgbuoba). A structured questionnaire with the outlined elements was utilized during data collection for the study: manner of living, type of occupation, environmental exposure, known health issues, fitness and cleanliness, and Key Informant Interviews (KII) were exploited to gain pertinent data from health professionals. A hand-held Kestrel weather tracker was employed to ascertain the wind speed, temperature, and relative humidity of the study areas while A Met One Instrument, Inc. Aerosol Mass Monitor Model GT-531 was utilized to estimate total suspended particulates. Biochemical parameters such as lipid profile, renal markers, and liver markers activities were analyzed from blood samples obtained from the subjects using spectrophotometric methods. The air quality profile of Mgbuoba showed significant (p < .05) increment in total suspended particulate matter, total suspended particulate matter (TSPM), particulate matter that is 10 microns in diameter or less (PM₁₀), and particulate matter that is 2.5 microns in diameter or less (PM_2.5) from 6 a.m. to 8 a.m. compared with Choba. The increment in Total suspended particulate matter, PM₁₀, and PM_2.5 levels were beyond the 24-hour PM₁₀ and PM_2.5 recommended level by the World Health Organization (WHO). The alanine transaminase (ALT) and low density lipoproptein (LDL) levels of Choba and Mgbuoba residents were beyond the reference limits set by the Medical Council of Canada. The study showed that residents in Mgbuoba in Port Harcourt may be more at risk and have higher vulnerability to the undesirable outcomes associated with exposures to these air contaminants. A rising and worrisome trend in respiratory and related conditions among less mobile residents call for emergency response to emission of black soot in the area.Implications: The study investigated the health profile of individuals exposed to particulate matter (Black) soot in Choba and Mgbuoba localities of Port Harcourt. This outcome clearly shows that these air pollutants are higher in concentrations early in the morning and their concentrations decreased as the day went by. Therefore, by implication, the residents in these areas may be at high risk of exposure to these air pollutants from 6 a.m. to 8 a.m. The present study has demonstrated that these air pollutants are more prominent very early in the mornings and variations in meteorological conditions at a particular time, and anthropogenic activities might have contributed to the elevations in the concentration of TSPM, PM₁₀, and PM_2.5 in Choba and Mgbuoba.

Short-term associations between particulate matter air pollution and hospital admissions through the emergency room for urinary system disease in Beijing, China: A time-series study

Evidence on the relationship between particulate matter air pollution and urinary system disease (UD) is scarce. This study aims to evaluate the associations between short-term exposures to PM_2.5 and PM₁₀ and risk of daily UD inpatient hospital admissions through the emergency room (ER-admissions) in Beijing. We obtained 41,203 weekday UD ER-admissions for secondary and tertiary hospitals in all 16 districts in Beijing during 2013-2018 from the Beijing Municipal Health Commission Information Center and obtained district-level air pollution concentrations based on 35 fixed monitoring stations in Beijing. We conducted a two-stage time-series analysis, with district-specific generalized linear models for each of Beijing's 16 districts, followed by random effects meta-analysis to obtain pooled risk estimates. We evaluated lagged and cumulative associations up to 30 days. In single-pollutant models, for both PM_2.5 and PM₁₀, cumulative exposure averaged over the day of admission and the previous 10 days (lag 0-10 days) showed the strongest association, with per interquartile range increases of PM_2.5 or PM₁₀ concentrations associated with a 7.5 % (95 % confidence interval [CI]: 3.0 %-12.2 %) or 6.0 % (95 % CI: 1.1 %-11.2 %) increased risk of daily UD hospital admissions, respectively. The risk estimates were robust to adjustment for co-pollutants and to a variety of sensitivity analyses. However, due to the strong correlation between PM_2.5 and PM₁₀ concentrations, we were unable to disentangle the respective relationships between these two exposures and UD risk. In this study, we found that short-term exposures to PM_2.5 and PM₁₀ are risk factors for UD morbidity and that cumulative exposure to PM pollution over a period of one to two weeks (i.e., 11 days) could be more important for UD risk than transient exposure during each of the respective single days.

Emerging role of air pollution in chronic kidney disease

Chronic kidney disease (CKD), a global disease burden related to high rates of incidence and mortality, manifests as progressive and irretrievable nephron loss and decreased kidney regeneration capacity. Emerging studies have suggested that exposure to air pollution is closely relevant to increased risk of CKD, CKD progression and end-stage kidney disease (ESKD). Inhaled airborne particles may cause vascular injury, intraglomerular hypertension, or glomerulosclerosis through non-hemodynamic and hemodynamic factors with multiple complex interactions. The mechanisms linking air pollutants exposure to CKD include elevated blood pressure, worsening oxidative stress and inflammatory response, DNA damage and abnormal metabolic changes to aggravate kidney damage. In the present review, we will discuss the epidemiologic observations linking air pollutants exposure to the incidence and progression of CKD. Then, we elaborate the potential roles of several air pollutants including particulate matter and gaseous co-pollutants, environmental tobacco smoke, and gaseous heavy metals in its pathogenesis. Finally, this review outlines the latent effect of air pollution in ESKD patients undergoing dialysis or renal transplant, kidney cancer and other kidney diseases. The information obtained may be beneficial for further elucidating the pathogenesis of CKD and making proper preventive strategies for this disease.

Urinary level of un-metabolized parabens in women working in beauty salons

Parabens are a group of chemical additive extensively utilized in various health care products and ubiquitously observed in the different environmental matrixes. Nevertheless, the exposure of women working in beauty salons to these pollutants is not well-documented. For this purpose, 50.00 women working in beauty salons were chosen as the exposed group (EG) and 35.00 housewives were chosen as the control group (GC). The concentration of methyl paraben (MeP), ethyl paraben (EtP), butyl paraben (BuP), propyl paraben (PrP), benzyl paraben (BzP), heptyl paraben (HepP), and para-hydroxybenzoic acid (4-HB) metabolite were quantified in the collected urine samples. It was seen that paraben sexist with a high detection frequency (DF) in the urine of women working in beauty salons. The results also revealed that the significant difference between the urinary parabens level in the EG and CG (P value < 0.05). The median concentration of Σparaben and HB-4 metabolite in the before exposure (BE) samples was 124.00 and 219.00 μg/L, while in the after exposure (AE) samples, it was 156.00 and 249.00 μg/L, respectively. Moreover, the parabens levels in the AE samples were considerably higher than in BE samples in women working in beauty salons (P value < 0.05). This research also documented that "personal care products (PCPs) usage" can be known as a leading factor for the urinary paraben level in the studied individuals. The median total estimated daily intakes (TEsDI) for MeP, EtP, and PrP for the studied women were obtained as 8.02, 4.57, and 7.88 μg/L respectively. Also, a significant and positive association was observed between EtP, PrP as well as BuP and 8-OhdG (as a DNA oxidative stress biomarker) (P value < 0.01). Further, a significant and positive association was found between EtP as well as BuP and some biomarkers of kidney damage (like uTIMP-1 and uKim-1). Accordingly, it can be stated that women working in beauty salons are at a high risk in terms of DNA oxidative stress and kidney damage.

Inflammatory response in human alveolar epithelial cells after TiO2 NPs or ZnO NPs exposure: Inhibition of surfactant protein A expression as an indicator for loss of lung function

The increasing use of metal oxide nanoparticles (MONPs) as TiO₂ NPs or ZnO NPs has led to environmental release and human exposure. The respiratory system, effects on lamellar bodies and surfactant protein A (SP-A) of pneumocytes, can be importantly affected. Exposure of human alveolar epithelial cells (A549) induced differential responses; a higher persistence of TiO₂ in cell surface and uptake (measured by Atomic Force Microscopy) and sustained inflammatory response (by means of TNF-α, IL-10, and IL-6 release) and ROS generation were observed, whereas ZnO showed a modest response and low numbers in cell surface. A reduction in SP-A levels at 24 h of exposure to TiO₂ NPs (concentration-dependent) or ZnO NPs (the higher concentration) was also observed, reversed by blocking the inflammatory response (by the inhibition of IL-6). Loss of SP-A represents a relevant target of MONPs-induced inflammatory response that could contribute to cellular damage and loss of lung function.

Clinical outcomes associated with long-term exposure to airborne particulate pollution in kidney transplant recipients

BACKGROUND

Researchers have yet to investigate the specific association between 10-μm particulate matter (PM10) levels and the risk of graft failure, kidney disease, or the functional decline of transplanted kidneys, in kidney transplant recipients (KTRs). Furthermore, we know very little about the association between PM10 levels and the development of allograft rejection in transplanted kidneys. Identification of air pollution as a potential contributor to kidney disease could help reduce future disease burden, stimulate policy discussions on the importance of reducing air pollution with respect to health and disease, and increase public awareness of the hazards of air pollution. We aimed to evaluate the relationship of PM10 with the risk of graft failure, mortality, and decline of graft function in KTRs.

METHODS

Air pollutant data were obtained from the Korean National Institute of Environmental Research. We then investigated potential associations between these data and the clinical outcomes of 1532 KTRs who underwent kidney transplantation in a tertiary hospital between 2001 and 2015. Survival models were used to evaluate the association between PM10 concentrations and the risk of death-censored graft failure (DCGF), all-cause mortality, and biopsy-proven rejection (BPR), over a median follow-up period of 6.31 years.

RESULTS

The annual mean PM10 exposure after kidney transplantation was 27.1 ± 8.0 μg/m3. Based on 1-year baseline exposure, 1 μg/m3 increase in PM10 concentration was associated with an increased risk of DCGF (hazard ratio (HR): 1.049; 95% confidence interval (CI): 1.014-1.084) and BPR (HR: 1.053; 95% CI: 1.042-1.063). Fully adjusted models showed that all-cause mortality was significantly associated with 1-year average PM10 concentrations (HR, 1.09; 95% CI, 1.043 to 1.140).

CONCLUSIONS

Long-term PM10 exposure is significantly associated with BPR, DCGF, and all-cause mortality in KTRs.

2-Undecanone Protects against Fine Particle-Induced Kidney Inflammation via Inducing Mitophagy

Exposure to particulate matter has been associated with diseases of the respiratory and cardiovascular systems. Owing to the dense vasculature of the kidney, it has also been identified as a PM_2.5 target organ. A potential contributor to PM_2.5-mediated damage may be the promotion of inflammation. The essential oil 2-undecanone (2-methyl nonyl ketone) is an H. cordata isolate, and it has been shown to possess diverse pharmacologic effects, including anti-inflammatory properties. In this study we explored the ability of 2-undecanone to protect against PM_2.5-induced kidney inflammation and the exact mechanisms in this process. We found that PM_2.5 elevated the levels of certain inflammatory cytokines in BALB/c mice and in HEK 293 cells. Supplementation with 2-undecanone attenuated this PM_2.5-induced inflammatory injury. Interestingly, in HEK 293 cells, the PM_2.5-associated inflammation was aggravated by the mitophagy inhibitor Medivi-1, while it was attenuated by rapamycin, indicating that the mechanism of 2-undecanone-mediated inhibition of inflammation may relate to mitophagy. Meanwhile, 2-undecanone induces mitophagy in HEK 293 cells by suppressing Akt1-mTOR signaling. These results indicate that PM_2.5 can induce kidney inflammation, and mitophagy induced by 2-undecanone may play a protective role against this renal inflammation.

Acute kidney damage by PM2.5 exposure in a rat model

PM2.5 exposure is associated with a glomerular filtration rate (GFR) reduction, and renal tissue damage. The goal of this study was demonstrate the acute effect of PM2.5 on the kidney. Male rats were acutely exposed to PM2.5 or filtered air. Blood pressure was mesure and early kidney biomarkers were evaluated in serum and urine samples, and also IL-1β, IL-6 and TNFα were determined. Oxidative biomarkers, angiotensin/bradykinin-related proteins, KIM-1, IL-6 and histology were determined. Blood pressure, GFR, and early kidney damage biomarkers increase together with oxidative biomarkers and angiotensin/bradykinin endocrine-related proteins increased after exposure to PM2.5. Urinary IL-6 increased after exposure to PM2.5, whereas in kidney cortex decreased. Histological changes were observed and accompanied by the induction of KIM-1. Acute exposure to PM2.5 not decline kidney function. However, it can induce early kidney damage biomarkers, oxidative stress, inflammation and angiotensin mediators, which perhabs culminates in a lose of renal function.

Short-term effects of size-fractionated particulate matters and their constituents on renal function in children: A panel study

Evidence available on the effects of size-fractionated particulate matters and their constituents on children's renal function is lack. We conducted a longitudinal panel study among 144 children aged 4-12 years with up to 3 repeated visits from 2018 to 2019. We estimated the effects of size-fractionated particle number counts (PNCs) and their 13 constituents on estimated glomerular filtration rate (eGFR) over different lag times with linear mixed-effects models and Bayesian kernel machine regression. We found the inverse dose-responsive associations of 3 sizes PNCs with eGFR were the strongest at lag 2 day. Compared to PNC_0.5, PNC₁ and PNC_2.5 showed stronger and similar effects on eGFR reduction. On average, an interquartile range increase in PNC_0.5, PNC₁ and PNC_2.5 were significantly associated with 1.70%, 2.82% and 2.76% decrease in eGFR, respectively. Girls were more susceptible to the toxicity of PNC₁ and PNC_2.5 exposure on eGFR. Several constituents including organic carbon (OC), Mg⁺, PO₃^- and HC₂O₄^- in 3 sizes PNCs were robustly and consistently linked to eGFR reduction at lag 2 day. Moreover, the cumulative effects of different constituents on lower eGFR were significant, when they were all at or above a size-independent threshold (the 60th, 65th, and 70th percentiles in PNC_0.5, PNC₁ and PNC_2.5 constituents, respectively), compared to their median value. And only OC displayed a significantly detrimental effect on eGFR when all the other constituents were fixed at 25th, 50th, and 75th percentiles. In summary, short-term exposure to PNCs were size-dependent related to reduced eGFR in dose-responsive manner among healthy children, and OC might play a more important role in PNC-induced nephrotoxicity than others.