Ambient Air Pollution and Biomarkers of Health Effect

Long-term air pollution exposure and the blood metabolome: The rotterdam study

BACKGROUND

Air pollution is a well-established risk factor for several adverse health outcomes, but the specific molecular mechanisms, particularly those involving metabolic processes, remain incompletely understood.

OBJECTIVE

To evaluate associations between long-term air pollutant exposure and circulating plasma metabolites in two sub-cohorts of the population-based Rotterdam Study.

METHODS

We analyzed data from 1455 participants of sub-cohort I (mean age 76.9 years, 58% female, 2002-2004) and 1061 participants from sub-cohort III (mean age 62.6 years, 56% female, 2012-2014). Mean annual exposure to fine particulate matter (PM2.5), black carbon, nitrogen dioxide, and ozone (measured both annually and in warm seasons only) were estimated at residential addresses using land use regression models. Plasma metabolites were measured by Metabolon Inc., using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. Cross-sectional associations between each air pollutant and 940 metabolites were determined using linear regression models. Benjamini-Hochberg false discovery rate (FDR) was utilized to control for multiple testing. Enrichment analysis was performed on statistically significant associated metabolites to identify significant metabolic pathways (p-value <0.05).

RESULTS

In sub-cohort I, PM2.5, black carbon, nitrogen dioxide, annual ozone and ozone in warm season were statistically significantly associated with, respectively, 63, 30, 20, 31, and 41 metabolites (FDR <0.05) mostly belonging to lipid and amino acid sub-classes, and unannotated metabolites. Sphinganine, X - 16576 and 2-pyrrolidinone displayed statistically significant associations across all five air pollutants. In sub-cohort III, black carbon, nitrogen dioxide and ozone in warm seasons were associated with a single unannotated metabolite (X - 24970), and annual ozone with two unannotated metabolites (X - 24970 and X - 24306). Enriched pathways identified in sub-cohort I included pyrimidine metabolism and steroid hormone biosynthesis.

CONCLUSIONS

Our study revealed associations of long-term air pollutant exposure with several metabolites and enrichment of two pathways, which are known to be involved in the adrenal and reproductive system and cell metabolism.

Health effects of air pollutant mixtures (volatile organic compounds, particulate matter, sulfur and nitrogen oxides) - a review of the literature

The health risks associated with individual air pollutant exposures have been studied and documented, but in real-life, the population is exposed to a multitude of different substances, designated as mixtures. A body of literature on air pollutants indicated that the next step in air pollution research is investigating pollutant mixtures and their potential impacts on health, as a risk assessment of individual air pollutants may actually underestimate the overall risks. This review aims to synthesize the health effects related to air pollutant mixtures containing selected pollutants such as: volatile organic compounds, particulate matter, sulfur and nitrogen oxides. For this review, the PubMed database was used to search for articles published within the last decade, and we included studies assessing the associations between air pollutant mixtures and health effects. The literature search was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A number of 110 studies were included in the review from which data on pollutant mixtures, health effects, methods used, and primary results were extracted. Our review emphasized that there are a relatively small number of studies addressing the health effects of air pollutants as mixtures and there is a gap in knowledge regarding the health effects associated with these mixtures. Studying the health effects of air pollutant mixtures is challenging due to the complexity of components that mixtures may contain, and the possible interactions these different components may have.

Differential effects of long- and short-term exposure to PM2.5 on accelerating telomere shortening: from in vitro to epidemiological studies

Exposure to air pollutants has been associated with DNA damage and increases the risks of respiratory diseases, such as asthma and COPD; however short- and long-term effects of air pollutants on telomere dysfunction remain unclear. We investigated the impact of short- and long-term exposure to fine particulate matter with an aerodynamic diameter below 2.5 μm (PM2.5) on telomere length in human bronchial epithelial BEAS-2B cells, and assessed the potential correlation between PM2.5 exposure and telomere length in the LIGHTS childhood cohort study. We observed that long-term, but not short-term, PM2.5 exposure was significantly associated with telomere shortening, along with the downregulation of human telomerase reverse transcriptase (hTERT) mRNA and protein levels. Moreover, long-term exposure to PM2.5 induced proinflammatory cytokine secretion, notably interleukin 6 (IL-6) and IL-8, triggered subG1 cell cycle arrest, and ultimately caused cell death. Long-term exposure to PM2.5 upregulated the LC3-II/ LC3-I ratio but led to p62 protein accumulation in BEAS-2B cells, suggesting a blockade of autophagic flux. Moreover, consistent with our in vitro findings, our epidemiological study found significant association between annual average exposure to higher PM2.5 and shortening of leukocyte telomere length in children. However, no significant association between 7-day short-term exposure to PM2.5 and leukocyte telomere length was observed in children. By combining in vitro experimental and epidemiological studies, our findings provide supportive evidence linking potential regulatory mechanisms to population level with respect to long-term PM2.5 exposure to telomere shortening in humans.

The effect of indoor air filtration on biomarkers of inflammation and oxidative stress: a review and meta-analysis of randomized controlled trials

Improvement of indoor air quality is beneficial for human health. However, previous studies have not reached consistent conclusions regarding the effects of indoor air filtration on inflammation and oxidative stress. This study aims to determine the relationship between indoor air filtration and inflammation and oxidative stress biomarkers. We conducted an electronic search that evaluated the association of indoor air filtration with biomarkers of inflammation and oxidative stress in five databases (PubMed, Cochrane Library, EMBASE, Web of Science, and Scopus) from the beginning to April 23, 2023. Outcomes included the following markers: interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), malondialdehyde (MDA), 8-hydroxy-2deoxyguanosine (8-OHdG), and 8-iso-prostaglandinF2α (8-isoPGF2α). We extracted data from the included studies according to the system evaluation and the preferred reporting item for meta-analysis (PRISMA) guidelines and used the Cochrane risk of bias tool to assess bias risk. Our meta-analysis included 15 studies with 678 participants to assess the combined effect size. The meta-analysis demonstrated that indoor air filtration could have a marked reduction in IL-6 (SMD: -0.275, 95% CI: -0.545 to -0.005, p = 0.046) but had no significant effect on other markers of inflammation or oxidative stress. Subgroup analysis results demonstrated a significant reduction in 8-OHdG levels in the subgroup with < 1 day of duration (SMD: -0.916, 95% CI: -1.513 to -0.320; p = 0.003) and using filtrete air filter (SMD: -5.530, 95% CI: -5.962 to -5.099; p < 0.001). Our meta-analysis results depicted that indoor air filtration can significantly reduce levels of inflammation and oxidative stress markers. Considering the adverse effects of air pollution on human health, our study provides powerful evidence for applying indoor air filtration to heavy atmospheric pollution.

Air pollution, cardiorespiratory fitness and biomarkers of oxidative status and inflammation in the 4HAIE study

The aim of this study was to investigate the associations between cardiorespiratory fitness (CRF), long-term air pollution exposure and biochemical markers of oxidative status and inflammation. This is a cross-sectional investigation focusing on biochemical markers of oxidative status and inflammation. Participants were Caucasian (N = 1188; age 18-65 years) who lived for at least 5 years in a high air-polluted (Moravian-Silesian; MS) or low air-polluted (South Bohemia; SB) region of the Czech Republic. Healthy runners and inactive individuals were recruited. A multiple regression analysis was used to explain the relationship between multiple independent variables (CRF, trunk fat mass, sex, socioeconomic status, and region (MS region vs. SB region) and dependent variables (oxidative status, inflammation). CRF, trunk fat mass, age and sex significantly predicted almost all selected markers of oxidative status and inflammation (except GSSG, GSH/GSSG and BDNF). Participants living in the MS region presented significantly higher GPx (by 3.1%) and lower BDNF values (by 4.5%). All other investigated biochemical markers were not significantly influenced by region. We did not find meaningful interactions between long-term air-pollution exposure versus markers of oxidative status and inflammation. However, we showed various significant interactions with sex, age, CRF and body composition. The significant association of living in the high air polluted MS region with the BDNF level warrants further attention.

Air pollution exposure and plasma fatty acid profile in pregnant women: a cohort study

Air pollution exposure was known to result in body impairments by inducing inflammation and oxidation. But little is known about the associations of air pollutants with plasma fatty acid profile which may play important roles in the impairment of air pollutants based on the related mechanism, especially in pregnant women. This study aimed to explore the relationships of air pollution exposure with plasma fatty acid profile and the potential effect modification by pre-pregnancy body mass index (BMI). Based on a cohort in Wuhan, China, we measured concentrations of plasma fatty acids of 519 pregnant women enrolled from 2013 to 2016 by gas chromatography-mass spectrometry (GC-MS). Levels of exposure to air pollutants (fine particulate matter (PM2.5), inhalable particles (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO)) were estimated by using spatial-temporal land use regression models and calculated in three periods (average concentrations during 1 day, 1 week, and 1 month before the phlebotomizing day in the first trimester). Per interquartile range increment of the levels of air pollution exposure 1 day before phlebotomizing was related to 1.21-2.01% increment of omega-6 polyunsaturated fatty acids (n-6PUFA) and 0.63-1.74% decrement of omega-3 polyunsaturated fatty acids (n-3PUFA). Besides, relationships above were kept robust in the analysis during 1 week and 1 month before phlebotomizing. In women with normal BMI, plasma fatty acid profile was observed to be more sensitive to air pollutants. Our study demonstrated that increment of exposure to air pollutants was associated with higher plasma n-6PUFA known to be pro-inflammatory and lower plasma n-3PUFA known to be anti-inflammatory, which was more sensitive in pregnant women with normal BMI. Our findings suggested that changes in plasma fatty acid profile should cause concerns and may serve as biomarkers in the further studies. Future studies are needed to validate our findings and elucidate the underlying mechanisms.

Effect of short-term exposure to ambient air pollutants on non-accidental mortality in emergency department visits: a time-series study

Objectives

Exposure to air pollution has been linked to an increased risk of premature mortality. However, the acute effects of air pollution on the risk of non-accidental mortality have not been extensively researched in developing countries, and the findings thus far have been inconsistent. Therefore, this study aimed to examine the association between short-term exposure to six pollutants (PM_2.5, PM₁₀, SO₂, NO₂, O₃, and CO) and non-accidental mortality in Beijing, China.

Methods

Daily data on non-accidental deaths were gathered from 1 January 2017 to 31 December 2018. Air pollution data for the same period were collected from 35 fixed-site air quality monitoring stations in Beijing. Generalized additive models (GAM) based on Poisson regression were used to investigate the association between non-accidental mortality in emergency department visits and the daily average levels of air pollutants.

Results

There were 8,676 non-accidental deaths recorded during 2017-2018. After sensitivity analysis, short-term exposure to air pollutants, particularly gaseous pollutants, was linked to non-accidental mortality. Specifically, for every 10 μg/m³ increase (5 μg/m³ in SO₂, 0.5 mg/m³ in CO) of SO₂ (lag 04), NO₂ (lag 04), O₃ (lag 05), and CO (lag 04), the relative risk (RR) values were 1.054 (95% CI: 1.009, 1.100), 1.038 (95% CI: 1.013, 1.063), 1.032 (95% CI: 1.011, 1.054), and 1.034 (95% CI: 1.004, 1.066), respectively. In terms of causes of death, short-term exposure to NO₂, SO₂, and O₃ increased the risk of circulatory mortality. Further stratified analysis revealed that the stronger associations were presented in females for O₃ while in males for CO. People aged 65 and over were strongly associated with ambient air pollution.

Conclusions

Our study showed that ambient air pollutants were associated with non-accidental mortality. Our findings suggested that efforts to control gaseous pollution should be stepped up, and vulnerable groups should be the focus of health protection education.

Association between ambient air pollutants and lipid profile: A systematic review and meta-analysis

BACKGROUND

Studies of the effects of atmospheric pollutants on lipid profiles remain inconsistent and controversial.

AIM

The study was aimed to investigate the relationship between the exposure to ambient air pollutants and variations in the blood lipid profiles in the population.

METHODS

A comprehensive search of three different databases (PubMed, Web of Science, and the Cochrane Library) until December 17, 2022, yielded 17 origional studies fulfilling the inclusion criteria for a meta-analysis. Aggregate effect measures and 95% confidence intervals (95% CI) for the relevant ambient air pollutants were deduced employing random effects models.

RESULTS

The collective meta-analysis indicated that long-term exposure to PM₁, PM_2.5, PM₁₀ and CO showed a substantial correlation with TC (PM₁: β = 2.04, 95%CI = 0.15-3.94; PM_2.5: β = 1.11, 95%CI = 0.39-1.84; PM₁₀: β = 1.70, 95%CI = 0.67-2.73; CO: β = 0.08, 95%CI = 0.06-0.10), PM₁₀ exhibited a significant association with TG (β = 0. 537,95% CI = 0.09-0.97), whereas HDL-C demonstrated notable relationships with PM₁, PM₁₀, SO₂ and CO (PM₁: β = -2.38, 95%CI = -4.00 to -2.76; PM₁₀: β = -0.77, 95%CI = -1.33 to -0.21; SO₂: β = -0.91, 95%CI = -1.73 to -0.10; CO: β = -0.03, 95%CI = -0.05 to 0.00). PM_2.5, PM₁₀ also showed significant associations with LDL-C (PM_2.5: β = 1.44 95%CI = 0.48-2.40; PM₁₀: β = 1.62 95%CI = 0.90-2.34). Subgroup analysis revealed significant or stronger correlations predominantly in cohort study designs, with higher male comparisons, and in regions exhibiting elevated contaminant levels.

CONCLUSION

In summary, the analysis substantiates that ambient air pollutants can be recognized as potent contributors to alterations in lipid profiles, particularly particulate pollutants which exert more obvious effects on lipid profiles.

Ecological study of ambient air pollution exposure and mortality of cardiovascular diseases in elderly

As an independent risk factor, ambient air pollution can assume a considerable part in mortality and worsening of cardiovascular disease. We sought to investigate the association between long-term exposure to ambient air pollution and cardiovascular disease mortality and their risk factors in Iranian's elderly population. This inquiry was conducted ecologically utilizing recorded data on cardiovascular disease mortality from 1990 to 2019 for males and females aged 50 years or more from the Global Burden of Disease dataset. Data was interned into Joinpoint software 4.9.0.0 to present Annual Percent Change (APC), Average Annual Percent Change (AAPC), and its confidence intervals. The relationship between recorded data on ambient air pollution and cardiovascular disease' mortality, the prevalence of high systolic blood pressure, high LDL cholesterol levels, high body mass index, and diabetes mellitus type2 was investigated using the Spearman correlation test in R 3.5.0 software. Our finding demonstrated that cardiovascular diseases in elderly males and females in Iran had a general decreasing trend (AAPC = -0.77% and -0.65%, respectively). The results showed a positive correlation between exposure to ambient ozone pollution (p ≤ 0.001, r = 0.94) ambient particulate and air pollution (p < 0.001, r = 0.99) and mortality of cardiovascular disease. Also, ambient air pollution was positively correlated with high systolic blood pressure (p < 0.001, r = 0.98), high LDL cholesterol levels (p < 0.001, r = 0.97), high body mass index (p < 0.001, r = 0.91), diabetes mellitus type2 (p < 0.001, r = 0.77). Evidence from this study indicated that ambient air pollution, directly and indirectly, affects cardiovascular disease mortality in two ways by increasing the prevalence of some traditional cardiovascular disease risk factors. Evidence-based clinical and public health methodologies are necessary to decrease the burden of death and disability associated with cardiovascular disease.

Effects of air pollution on telomere length: Evidence from in vitro to clinical studies

Air pollution remains the major environmental problem globally. There is extensive evidence showing that the variety of air pollutants from environmental and occupational exposures cause adverse effects to our health. The clinical symptoms of those effects may present at a late stage, so surveillance is difficult to manage. Several biomarkers have been used for the early detection of health issues following exposure to air pollution, including the use of telomere length which indicates cellular senescence in response to oxidative stress. Oxidative stress is one of the most plausible mechanisms associated with exposure to air pollutants. Some specific contexts including age groups, gender, ethnicity, occupations, and health conditions, showed significant alterations in telomere length after exposure to air pollutants. Several reports demonstrated both negative and positive associations between telomere length and air pollution, the studies using different concentrations and exposure times to air pollution on the study of telomere lengths. Surprisingly, some studies reported that low levels of exposure to air pollutants (lower than regulated levels) caused the alterations in telomere length. Those findings suggest that telomere length could be one of most practical biomarkers in air pollution surveillance. Therefore, this review aimed to summarize and discuss the relationship between telomere length and exposure to air pollution. The knowledge from this review will be beneficial for the planning of public health to reduce health problems in the general population, particularly in vulnerable people, who still live in areas with high air pollution.

Exposure to outdoor and indoor air pollution and risk of overweight and obesity across different life periods: A review

Due to the highly evolved industrialization and modernization, air quality has deteriorated in most countries. As reported by the World Health Organization (WHO), air pollution is now considered as one of the major threats to global health and a principal risk factor for noncommunicable diseases. Meanwhile, the increasing worldwide prevalence of overweight and obesity is attracting more public attentions. Recently, accumulating epidemiological studies have provided evidence that overweight and obesity may be partially attributable to environmental exposure to air pollution. This review summarizes the epidemiological evidence for the correlation between exposure to various outdoor and indoor air pollutants (mainly particulate matter (PM), nitrogen oxides (NO_x), ozone (O₃), and polycyclic aromatic hydrocarbons (PAHs)) and overweight and obesity outcomes in recent years. Moreover, it discusses the multiple effects of air pollution during exposure periods throughout life and sex differences in populations. This review also describes the potential mechanism underlying the increased risk of obesity caused by air pollution, including inflammation, oxidative stress, metabolic imbalance, intestinal flora disorders and epigenetic modifications. Finally, this review proposes macro- and micro-measures to prevent the negative effects of air pollution exposure on the obesity prevalence.

Polycyclic aromatic hydrocarbon and its effects on human health: An overeview

Polycyclic aromatic hydrocarbons (PAHs) are a class of chemicals of considerable environmental significance. PAHs are chemical contaminants of fused carbon and hydrogen aromatic rings, basically white, light-yellow, or solid compounds without color. Natural sources of pollution are marginal or less significant, such as volcanic eruptions, natural forest fires, and moorland fires that trigger lightning bursts. The significant determinants of PAH pollution are anthropogenic pollution sources, classified into four groups, i.e., industrial, mobile, domestic, and agricultural pollution sources. Humans can consume PAHs via different routes, such as inhalation, dermal touch, and ingestion. The Effect of PAHs on human health is primarily based on the duration and route of exposure, the volume or concentration of PAHs to which one is exposed, and the relative toxicity of PAHs. Many PAHs are widely referred to as carcinogens, mutagens, and teratogens and thus pose a significant danger to human health and the well-being of humans. Skin, lung, pancreas, esophagus, bladder, colon, and female breast are numerous organs prone to tumor development due to long-term PAH exposure. PAH exposure may increase the risk of lung cancer as well as cardiovascular disease (CVD), including atherosclerosis, thrombosis, hypertension, and myocardial infarction (MI). Preclinical studies have found a relationship between PAH exposure, oxidative stress, and atherosclerosis. In addition, investigations have discovered a relationship between PAH exposure at work and CVD illness and mortality development. This review aims to explain PAH briefly, its transportation, its effects on human health, and a relationship between environmental exposures to PAHs and CVD risk in humans.

Short-term effect of meteorological factors on the risk of rheumatoid arthritis hospital admissions: A distributed lag non-linear analysis in Hefei, China

Rheumatoid arthritis (RA) is an autoimmune disease, mainly characterized by erosional arthritis. The proportion of adults suffering from RA is about 0.5%-1%. There have been reports on the association of rainfall and traffic-related air pollutants with RA hospitalization rates. However, there have been no studies on the association of diurnal temperature range (DTR) and relative humidity (RH) with RA hospitalization rates. This study aimed to examine the short-term association of DTR, RH and other meteorological factors with the hospital admission rate of RA patients, while excluding the interference of PM_2.5, SO₂, NO₂, CO and O₃ atmospheric pollutants. We collected daily RA occupancy rate and meteorological factor data in Hefei city from 2015 to 2018 and used the generalized additive model (GAM) combined with the distributed lag nonlinear model (DLNM) for time series analysis, and further stratified analysis by gender and age. Single-day and cumulative-day risk estimates of RA admissions were expressed as relative risk (RR) and its 95% confidence interval (95% CI). For the cumulative-day lag model, high RH was statistically significant after cumulative lag 0-8 days, and the effect gradually increases. Stratified analysis shows that females seem to be more susceptible to high or extremely high DTR and RH exposure, and extremely high DTR exposure may increase the risk of RA admission in all populations. In conclusion, this study found that high DTR and high RH exposure increased the risk of hospitalization in RA patients and provided clues to the potential association between other meteorological factors and RA.

Association Between Air Pollutants and Pediatric Respiratory Outpatient Visits in Zhoushan, China

Objective

This study aimed to explore the time-series relationship between air pollutants and the number of children's respiratory outpatient visits in coastal cities.

Methods

We used time series analysis to investigate the association between air pollution levels and pediatric respiratory outpatient visits in Zhoushan city, China. The population was selected from children aged 0–18 who had been in pediatric respiratory clinics for eight consecutive years from 2014 to 2020. After describing the population and weather characteristics, a lag model was used to explore the relationship between outpatient visits and air pollution.

Results

We recorded annual outpatient visits for different respiratory diseases in children. The best synergy lag model found a 10 μg/m³ increase in PM_2.5 for every 4–10% increase in the number of pediatric respiratory outpatient visits (P < 0.05). The cumulative effect of an increase in the number of daily pediatric respiratory clinics with a lag of 1–7 days was the best model.

Conclusions

PM_2.5 is significantly related to the number of respiratory outpatient visits of children, which can aid in formulating policies for health resource allocation and health risk assessment strategies.

Impact of air pollution exposure on the risk of Alzheimer's disease in China: A community-based cohort study

Alzheimer's disease (AD) is the most common type of dementia. Impact of air pollution (AP) on the risk of AD is unclear. It is unknown which air pollutants are independently associated with AD and whether fish consumption mitigated the association. We carried out a community-based cohort of 6115 participants aged ≥60 years in China to examine the association of PM_2.5, PM₁₀, CO, NO₂, SO₂ and O₃ exposure with AD, and differences in the association between people with low and high consumption of fish. The participants were randomly recruited from six counties in Zhejiang province for health survey to document socio-demographic and disease risk factors in 2014, and were followed up to diagnose AD in 2019. A total of 986 cohort members were diagnosed with AD. Based on the daily mean air pollutants monitored in 2013-2015 in the counties, participants were divided into low, middle and high AP exposure groups for subsequent analysis. The multiple adjusted odds ratio (OR) of AD in participants living with the middle and high levels of PM_2.5 exposure versus the low exposure were 1.50 (95% CI 0.90-2.50) and 3.92 (2.09-7.37). The increased ORs were also with PM₁₀ (1.74, 0.65-4.64; 3.00, 1.22-7.41) and CO (2.86, 1.32-6.20; 1.19, 0.45-3.18), but not with NO₂ (0.63, 0.17-2.27; 0.95, 0.28-3.19), SO₂ (0.44, 0.19-1.001; 1.21, 0.56-2.62), and O₃ (0.38, 0.20-0.74; 0.50, 0.21-1.21). There were no significant interaction effects of AP with fish consumption on AD. However, participants with low consumption of fish appeared to have higher ORs in PM_2.5 exposure (1.80, 1.39-2.33; 5.18, 3.93-6.82) than those high consumption (1.38, 0.78-2.47; 2.89, 1.50-5.59). Our findings of PM_2.5, PM₁₀ and CO exposure significantly increased the risk of AD and the potential mitigating effect of fish consumption on the association provide evidence for developing effective strategies for AD reduction and air pollution control.

Influence of PM1 exposure on total and cause-specific respiratory diseases: a systematic review and meta-analysis

An increasing number of studies examined the potential effects of PM1 (submicronic particulate matter with an aerodynamic diameter ≤ 1 μm) on the risk of respiratory diseases; however, the results have been inconclusive. This study aimed to determine the overall association between PM1 with total and cause-specific respiratory diseases. A systematic review and meta-analysis was conducted with 68 related articles retrieved, and six articles met the full inclusion criteria for the final analysis. For a 10 μg/m3 increase in PM1, the pooled odds ratio (OR) was 1.05 (95% CI 0.98-1.12) for total respiratory diseases, 1.25 (95% CI 1.00-1.56) for asthma, and 1.07 (95% CI 1.04-1.10) for pneumonia with the I2 value of 87%, 70%, and 0%, respectively. Subgroup analyses showed that long-term exposure to PM1 was associated with increased risk of asthma (OR 1.47, 95% CI 1.33-1.63) with an I2 value of 0%, while short-term exposure to PM1 was not associated with asthma (OR 1.07, 95% CI 0.89-1.27) with the I2 value of 0%. Egger's test showed that publication bias existed (P = 0.041); however, the funnel plot was symmetrical with the inclusion of the moderator. In conclusion, elevated levels of PM1 may increase morbidity in total and cause-specific respiratory diseases in the population.

Long-term exposure to PM10 above WHO guidelines exacerbates COVID-19 severity and mortality

BACKGROUND

Age, sex, race and comorbidities are insufficient to explain why some individuals remain asymptomatic after SARS-CoV-2 infection, while others die. In this sense, the increased risk caused by the long-term exposure to air pollution is being investigated to understand the high heterogeneity of the COVID-19 infection course.

OBJECTIVES

We aimed to assess the underlying effect of long-term exposure to NO2 and PM10 on the severity and mortality of COVID-19.

METHODS

A retrospective observational study was conducted with 2112 patients suffering COVID-19 infection. We built two sets of multivariate predictive models to assess the relationship between the long-term exposure to NO2 and PM10 and COVID-19 outcome. First, the probability of either death or severe COVID-19 outcome was predicted as a function of all the clinical variables together with the pollutants exposure by means of two regularized logistic regressions. Subsequently, two regularized linear regressions were constructed to predict the percentage of dead or severe patients. Finally, odds ratios and effects estimates were calculated.

RESULTS

We found that the long-term exposure to PM10 is a more important variable than some already stated comorbidities (i.e.: COPD/Asthma, diabetes, obesity) in the prediction of COVID-19 severity and mortality. PM10 showed the highest effects estimates (1.65, 95% CI 1.32-2.06) on COVID-19 severity. For mortality, the highest effect estimates corresponded to age (3.59, 95% CI 2.94-4.40), followed by PM10 (2.37, 95% CI 1.71-3.32). Finally, an increase of 1 µg/m3 in PM10 concentration causes an increase of 3.06% (95% CI 1.11%-4.25%) of patients suffering COVID-19 as a severe disease and an increase of 2.68% (95% CI 0.53%-5.58%) of deaths.

DISCUSSION

These results demonstrate that long-term PM10 burdens above WHO guidelines exacerbate COVID-19 health outcomes. Hence, WHO guidelines, the air quality standard established by the Directive 2008/50/EU, and that of the US-EPA should be updated accordingly to protect human health.

Long-term exposure to PM10 above WHO guidelines exacerbates COVID-19 severity and mortality

BACKGROUND

Age, sex, race and comorbidities are insufficient to explain why some individuals remain asymptomatic after SARS-CoV-2 infection, while others die. In this sense, the increased risk caused by the long-term exposure to air pollution is being investigated to understand the high heterogeneity of the COVID-19 infection course.

OBJECTIVES

We aimed to assess the underlying effect of long-term exposure to NO₂ and PM₁₀ on the severity and mortality of COVID-19.

METHODS

A retrospective observational study was conducted with 2112 patients suffering COVID-19 infection. We built two sets of multivariate predictive models to assess the relationship between the long-term exposure to NO₂ and PM₁₀ and COVID-19 outcome. First, the probability of either death or severe COVID-19 outcome was predicted as a function of all the clinical variables together with the pollutants exposure by means of two regularized logistic regressions. Subsequently, two regularized linear regressions were constructed to predict the percentage of dead or severe patients. Finally, odds ratios and effects estimates were calculated.

RESULTS

We found that the long-term exposure to PM₁₀ is a more important variable than some already stated comorbidities (i.e.: COPD/Asthma, diabetes, obesity) in the prediction of COVID-19 severity and mortality. PM₁₀ showed the highest effects estimates (1.65, 95% CI 1.32-2.06) on COVID-19 severity. For mortality, the highest effect estimates corresponded to age (3.59, 95% CI 2.94-4.40), followed by PM₁₀ (2.37, 95% CI 1.71-3.32). Finally, an increase of 1 µg/m³ in PM₁₀ concentration causes an increase of 3.06% (95% CI 1.11%-4.25%) of patients suffering COVID-19 as a severe disease and an increase of 2.68% (95% CI 0.53%-5.58%) of deaths.

DISCUSSION

These results demonstrate that long-term PM₁₀ burdens above WHO guidelines exacerbate COVID-19 health outcomes. Hence, WHO guidelines, the air quality standard established by the Directive 2008/50/EU, and that of the US-EPA should be updated accordingly to protect human health.

Is micronucleus assay in oral exfoliated cells a suitable tool for biomonitoring children exposed to environmental pollutants? A systematic review

The aim of this review was to evaluate if micronucleus assay in oral exfoliated cells is a suitable tool for biomonitoring children exposed to environmental pollutants. Through the electronic databases PubMed/Medline, Scopus, and Web of Science, all published studies until April 2021 that examined the relationship between exposure to environmental pollutants and micronucleus frequency in oral cells were searched. All relevant articles using a combination of the following keywords-"children," "micronucleus," "oral cells," and "environmental pollution"-were considered. A total of 20 papers met the criteria for inclusion in the systematic review. The results regarding the cytogenetic damage induced by environmental pollutants are conflicting. Some authors have demonstrated that environmental pollution induces mutagenesis in oral cells while others did not. Following the parameters of the Project for Effective Public Health Practices (EPHPP) and after extensive reading of all the articles included, a total of 12 articles had moderate and strong scores and 8 had a classification considered weak. Taken together, this review was able to demonstrate the association between micronucleus frequency and exposure to environmental pollutants in oral exfoliated cells of children.

Effects of short- and long-term exposure to air pollution and meteorological factors on Meniere's disease

The association between air pollutants and Meniere’s disease has not been explored. The present study investigated the relationship between meteorological factors and air pollutants on Meniere’s disease. Participants, aged ≥ 40 years, of the Korean National Health Insurance Service-Health Screening Cohort were included in this study. The 7725 patients with Meniere’s disease were matched with 30,900 control participants. The moving average meteorological and air pollution data of the previous 7 days, 1 month, 3 months, and 6 months before the onset of Meniere’s disease were compared between the Meniere’s disease and control groups using conditional logistic regression analyses. Additional analyses were conducted according to age, sex, income, and residential area. Temperature range; ambient atmospheric pressure; sunshine duration; and levels of SO₂, NO₂, O₃, CO, and PM₁₀ for 1 month and 6 months were associated with Meniere’s disease. Adjusted ORs (odds ratios with 95% confidence interval [CI]) for 1 and 6 months of O₃ concentration were 1.29 (95% CI 1.23–1.35) and 1.31 (95% CI 1.22–1.42), respectively; that for the 1 and 6 months of CO concentration were 3.34 (95% CI 2.39–4.68) and 4.19 (95% CI 2.79–6.30), respectively. Subgroup analyses indicated a steady relationship of O₃ and CO concentrations with Meniere’s disease. Meteorological factors and air pollutants were associated with the rate of Meniere’s disease. In particular, CO and O₃ concentrations were positively related to the occurrence of Meniere’s disease.

Polycyclic Aromatic Hydrocarbons from Fine Particulate Matter Induce Oxidative Stress and the Inflammatory Response in Human Vocal Fold Fibroblast Cells

Polycyclic aromatic hydrocarbons (PAHs) are toxicants in particulate matter (PM). The vocal fold, part of the larynx and a key structure for voicing, is always in contact with air. In recent epidemic studies, PM was shown to cause laryngitis; however, the basic mechanism has not been evaluated. In the present study, intracellular reactive oxygen species (ROS) and proinflammatory cytokine levels were analyzed after exposing human vocal fold fibroblasts (hVFFs) to PM standard reference material (SRM 2786). Expression levels of the aryl hydrocarbon receptor (AhR) and Cytochrome P450 Family 1 Subfamily A Member 1 (CYP1A1) were also evaluated. PM induced ROS formation and proinflammatory cytokines via the AhR CYP1A1 pathway and caused lipid peroxidation and DNA damage. Blocking AhR or CYP1A1 production using siRNAs significantly decreased ROS production and IL-6 and IL-9 expression in PM-exposed hVFFs, thus protecting the cells against oxidative stress. These results confirm that PAHs in PM play an important role in cell damage and inflammation, confirming a basic pathophysiologic relationship between PM exposure and laryngitis.

The association between short-term exposure to air pollutants and rotavirus infection in Wuhan, China

BACKGROUND

The impact of various meteorological factors on rotavirus (RV) infection has been previously studied; however, few studies have explored the association between short-term exposure to air pollutants and RV infection.

METHODS

Daily RV positive cases among children aged 0-6 years were collected from July 2014 to August 2019 in Tongji hospital (Wuhan, China). Daily data on air temperature and air pollutants were obtained from the China Meteorological Network. A distributed lag model to explore the lagged effects of short-term exposure to air pollutants and RV infection was performed. The distribution lag model was used to study the lag effect of short-term exposure to air pollutants and RV infection.

RESULTS

RV infection was negatively correlated with mean air temperature and O₃ concentration. The RV infection risk decreased by 5.2% and 0.47% for every 1℃ increase in average temperature and 1 ug/m³ increase in O₃ concentration, respectively. Increased PM_2.5 , SO₂ , and NO₂ concentrations were independent risk factors for an increase in positive rates; their relative risk values were 1.0014 (95% confidence interval [CI], 1.0013-1.0015), 1.0050 (95% CI, 1.0047-1.0053), and 1.0030 (95% CI, 1.0028-1.0032), respectively. The highest RV-positive rates were from January to March and November to December. Additionally, children <18 months of age and boys were more vulnerable to infection.

CONCLUSIONS

Air pollutants were important factors impacting the RV-positivity of children in Wuhan. These findings may help develop an early environment-based warning system to prevent and control RV infection.

Effects of domestic solid fuel combustion emissions on the biomarkers of homemakers in rural areas of the Fenwei Plain, China

BACKGROUND

The health effects of heavy solid fuel use in winter in rural China are of concern. The effects of air pollution resulting from domestic solid fuel combustion in rural households on rural homemakers' biomarkers were revealed in this study.

METHODS

In total, 75 female homemakers from rural areas of Guanzhong Basin, the Fenwei Plain, People's Republic of China, were randomly selected and divided into three groups (biomass users, coal users, and nonusers of solid fuel user [control group]). The differences in biological indicators, including 8-hydrox-2'-deoxyguanosine (8-OHdG), interlukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in urine samples as well as blood pressure (BP, including systolic BP [SBP] and diastolic BP [DBP]) and heart rate (HR) among the groups in winter and summer were investigated using statistical analysis.

RESULTS

IL-6, 8-OHdG, HR, SBP, and DBP were significantly higher in winter than in summer (P < 0.05) owing to the poor air quality resulted from the excessive use of solid fuels in winter. Significant seasonal differences in 8-OHdG were observed for both coal and biomass users. After the influence of confounders was removed, only IL-6 levels in the urine of solid fuel users were significantly higher than that of the control group.

CONCLUSIONS

IL-6 is a sensitive biomarker representing inflammatory responses to particulate matter emitted through household solid fuel combustion. Locally, excessive use of solid fuels in winter posed serious PM_2.5 pollution in this area and adverse effects on inflammatory biomarkers in these rural homemakers and induced DNA damage related to oxidative stress.

Comparison of respiratory and skin disorders between residents living close to and far from Solous landfill site in Lagos State, Nigeria

Background

Solid waste dump sites have proven to have potentially high risk to human health as it serves as a source of air, soil and underground water pollution.

Aim

This study aimed to assess and compare the knowledge, respiratory disorders and skin disorders between residents living close to and far from landfill sites in Lagos State, Nigeria.

Setting

Igando (a community within 5 km close to) and Badagry (a community beyond 5 km from) Solous Landfill sites in Lagos state, Nigeria.

Methods

A comparative cross-sectional study amongst 103 respondents recruited from each of the two study sites by multistage sampling method was carried out. Data were collected using pretested, structured, interviewer-administered questionnaire, and analysed using Microsoft Excel 2007, EPI Info 7 and WinPepi statistical software packages. Student t-test, Fisher’s exact and Chi-square tests were carried out. The p ≤ 0.05 was considered statistically significant.

Results

The mean age of Igando and Badagry respondents was 34.18 ± 10.21 years and 32.62 ± 9.84 years, respectively. The two communities differed significantly (p < 0.0001) with respect to distance of workplace from landfill site and duration of stay in the residential location. The mean knowledge score of respondents on respiratory and skin disorders associated with solid waste dump site close to landfill sites (82.53 ± 20.60) was statistically significantly higher than those of respondents far from landfill sites (71.84 ± 20.57) (p = 0.0003). Respiratory and skin disorders experiences of respondents close to landfill sites were statistically significantly (p < 0.0001) higher than those of residents far from landfill sites with respect to wheezing, frequent sneezing, unpleasant odour, fever and skin rashes.

Conclusion

Respiratory and skin disorders experienced by respondents close to landfill sites are higher than those of residents far from landfill sites. Landfill sites should not be located close to human settlements.

Differential effects of intense exercise and pollution on the airways in a murine model

Background

Exercise-induced bronchoconstriction (EIB) is a transient airway narrowing, occurring during or shortly after intensive exercise. It is highly prevalent in non-asthmatic outdoor endurance athletes suggesting an important contribution of air pollution in the development of EIB. Therefore, more research is necessary to investigate the combination of exercise and pollutants on the airways.

Methods

Balbc/ByJ mice were intranasally challenged 5 days a week for 3 weeks with saline or 0.2 mg/ml diesel exhaust particles (DEP), prior to a daily incremental running session or non-exercise session. Once a week, the early ventilatory response was measured and lung function was determined at day 24. Airway inflammation and cytokine levels were evaluated in bronchoalveolar lavage fluid. Furthermore, innate lymphoid cells, dendritic cells and tight junction mRNA expression were determined in lung tissue.

Results

Submaximal exercise resulted in acute alterations of the breathing pattern and significantly improved FEV_0.1 at day 24. DEP exposure induced neutrophilic airway inflammation, accompanied with increased percentages of CD11b⁺ DC in lung tissue and pro-inflammatory cytokines, such as IL-13, MCP-1, GM-CSF and KC. Occludin and claudin-1(Cldn-1) expression were respectively increased and decreased by DEP exposure. Whereas, exercise increased Cldn-3 and Cldn-18 expression. Combining exercise and DEP exposure resulted in significantly increased SP-D levels in the airways.

Conclusion

DEP exposure induced typical airway neutrophilia, DC recruitment and pro-inflammatory cytokine production. Whereas, intensive exercise induced changes of the breathing pattern. The combination of both triggers resulted in a dysregulation of tight junction expression, suggesting that intensive exercise in polluted environments can induce important changes in the airway physiology and integrity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-021-00401-6.

The Association of White Blood Cells and Air Pollutants-A Population-Based Study

The links of air pollutants to health hazards have been revealed in literature and inflammation responses might play key roles in the processes of diseases. WBC count is one of the indexes of inflammation, however the l iterature reveals inconsistent opinions on the relationship between WBC counts and exposure to air pollutants. The goal of this population-based observational study was to examine the associations between multiple air pollutants and WBC counts. This study recruited community subjects from Kaohsiung city. WBC count, demographic and health hazard habit data were collected. Meanwhile, air pollutants data (SO₂, NO₂, CO, PM₁₀, and O₃) were also obtained. Both datasets were merged for statistical analysis. Single- and multiple-pollutants models were adopted for the analysis. A total of 10,140 adults (43.2% males; age range, 33~86 years old) were recruited. Effects of short-term ambient concentrations (within one week) of CO could increase counts of WBC, neutrophils, monocytes, and lymphocytes. However, SO₂ could decrease counts of WBC, neutrophils, and monocytes. Gender, BMI, and smoking could also contribute to WBC count increases, though their effects are minor when compared to CO. Air pollutants, particularly SO₂, NO₂ and CO, may thus be related to alterations of WBC counts, and this would imply air pollution has an impact on human systematic inflammation.

Circadian Deregulation as Possible New Player in Pollution-Induced Tissue Damage

Circadian rhythms are 24-h oscillations driven by a hypothalamic master oscillator that entrains peripheral clocks in almost all cells, tissues and organs. Circadian misalignment, triggered by industrialization and modern lifestyles, has been linked to several pathological conditions, with possible impairment of the quality or even the very existence of life. Living organisms are continuously exposed to air pollutants, and among them, ozone or particulate matters (PMs) are considered to be among the most toxic to human health. In particular, exposure to environmental stressors may result not only in pulmonary and cardiovascular diseases, but, as it has been demonstrated in the last two decades, the skin can also be affected by pollution. In this context, we hypothesize that chronodistruption can exacerbate cell vulnerability to exogenous damaging agents, and we suggest a possible common mechanism of action in deregulation of the homeostasis of the pulmonary, cardiovascular and cutaneous tissues and in its involvement in the development of pathological conditions.

Regular running in an air-polluted environment: physiological and anthropometric protocol for a prospective cohort study (Healthy Aging in Industrial Environment Study - Program 4)

INTRODUCTION

Ambient air pollution is a global environmental problem, which causes adverse health effects and premature deaths worldwide. Although regular exercise and physical activity have evident health benefits, the influence of long-term air pollution exposure during regular outdoor running has not been definitively clarified.

METHODS AND ANALYSIS

This study protocol describes the physiological and anthropometric perspectives of the 'Healthy Aging in Industrial Environment' Study - Programme 4 (4HAIE). The 4HAIE research project is intended to be a single-centre, prospective, longitudinal and multidisciplinary cohort study. The presented study protocol describes the cross-sectional measurements and analyses. Overall, 1500 adult participants (age 18-65 years), runners and inactive individuals, living in a high or low air-polluted area of the Czech Republic will be recruited. We will measure and analyse biomarkers of oxidative stress and inflammation in the blood, exercise capacity (graded exercise test and spiroergometry), blood pressure, lung function (spirometry), cardiac autonomic regulation and anthropometry (body composition).

ETHICS AND DISSEMINATION

The 4HAIE study protocol has already been approved by the Ethics Committee of the University of Ostrava (3/2018). A detailed participant information sheet will be provided to each individual prior to obtaining their written informed consent. The study poses little to no risk to participants. The findings of this study will be disseminated at regional and international conferences, in peer-reviewed journals and via social and broadcast media.

Ambient air pollution and gestational diabetes mellitus: A review of evidence from biological mechanisms to population epidemiology

Gestational diabetes mellitus (GDM) is a serious complication of pregnancy that could cause adverse health effects on both mothers and fetuses, and its prevalence has been increasing worldwide. Experimental and epidemiological studies suggest that air pollution may be an important risk factor of GDM, but conclusions are inconsistent. To provide a comprehensive overview of ambient air pollution on GDM, we summarized existing evidence concerning biological linkages between maternal exposure to air pollutants and GDM based on mechanism studies. We also performed a quantitative meta-analysis based on human epidemiological studies by searching English databases (Pubmed, Web of Science and Embase) and Chinese databases (Wanfang, CNKI). As a result, the limited mechanism studies indicated that β-cell dysfunction, neurohormonal disturbance, inflammation, oxidative stress, imbalance of gut microbiome and insulin resistance may be involved in air pollution-GDM relationship, but few studies were performed to explore the direct biological linkage. Additionally, a total of 13 epidemiological studies were included in the meta-analysis, and the air pollutants considered included PM_2.5, PM₁₀, SO₂, NO₂ and O₃. Most studies were retrospective and mainly conducted in developed regions. The results of meta-analysis indicated that maternal first trimester exposure to SO₂ increased the risk of GDM (standardized odds ratio (OR) = 1.392, 95% confidence intervals (CI): 1.010, 1.773), while pre-pregnancy O₃ exposure was inversely associated with GDM risk (standardized OR = 0.981, 95% CI: 0.977, 0.985). No significant effects were observed for PM_2.5, PM₁₀ and NO₂. In conclusion, additional mechanism studies on the molecular level are needed to provide persuasive rationale underlying the air pollution-GDM relationship. Moreover, other important risk factors of GDM, including maternal lifestyle and road traffic noise exposure that may modify the air pollution-GDM relationship should be considered in future epidemiological studies. More prospective cohort studies are also warranted in developing countries with high levels of air pollution.

Comprehensive review of the current literature on impact of ambient air pollution and sleep quality

Air pollution is associated with increasing morbidity, mortality and decreasing health and life span. Accumulating epidemiological and experimental evidence has shown that exposure to ambient air pollutants such as particulate matters (PM) and gaseous components [eg, nitrogen dioxide (NO₂), ozone (O₃)] has detrimental effects on sleep quality. We conducted this comprehensive review to explore the association between ambient air pollution and sleep quality. A systematic search was conducted with the databases of PubMed and Web of Science from inception to November 2019. Overall, 15 studies with 133,695 subjects that evaluated the association between ambient air pollution and sleep quality were conducted in 10 different countries (ie, USA, Brazil, Canada, Chile, China, Egypt, Germany, Iran, Mexico, and Turkey). Most included studies in the current review have shown that one or more air pollutants have negative influences on sleep quality. Air pollutants might be one of the triggers for poor sleep quality via disparate mechanisms including but not limited to the central ventilator control centers, central nervous system, allergic and non-allergic mechanisms. The possible association between air pollution and select chronic diseases (eg, mental illnesses, cardiovascular diseases) and behaviors (eg, impulsivity) may also play important roles in explaining the association between ambient air pollution and sleep quality. The associations and underlying mechanisms between ambient air pollutants and sleep quality need to be clarified with long-term, multi-centered cohort studies.

Maternal exposure to air pollution during pregnancy and cortisol level in cord blood

Exposure to air pollution has been associated with disorders of the endocrine system and hypothalamic-pituitary-adrenal (HPA) axis; however, the available evidence on these associations is still scarce. This study aimed to investigate, for the first time, the association of exposure to PM₁, PM_2.5, and PM₁₀, as well as traffic indicators (distance to major roads and total street length in different buffers around maternal residential address) during pregnancy with cortisol level in cord blood samples. This cross-sectional study was carried out based on 150 mother-newborn pairs in Sabzevar, Iran (2018). Land use regression models were applied to estimate air pollution exposure during the entire pregnancy at maternal residential addresses. Multiple linear regression models were applied to estimate the association of exposure to air pollution during pregnancy and cord blood cortisol levels, controlled for relevant covariates. There was a significant positive association between exposure to PM_2.5 and PM₁₀ and cortisol levels in cord blood (β = 2.55, 95% confidence intervals (CI) = 0.57, 4.52, P-value = 0.01, and β = 3.09, 95% CI: 1.28, 4.90, P-value < 0.01, respectively). Moreover, there was a significant positive association between total street length in a 100 m buffer around maternal residence and cortisol level. Each one interquartile range (IQR) increase in distance from home to major roads was associated with a -2.58 (95% CI: -4.85, -0.30, P-value = 0.03) decrease in cord blood cortisol level. The median (IQR) of the cord blood cortisol levels for the first and fourth quartiles of distance to major roads were 50.7 (19.5) and 38.2 (20.4) ng/mL, respectively. The associations for total street length in 300 m and 500 m buffers and PM₁ exposure were not statistically significant. Our findings suggest a direct association of exposure to air pollution during pregnancy and cortisol levels at cord blood.

Associations between ambient air pollution and mortality from all causes, pneumonia, and congenital heart diseases among children aged under 5 years in Beijing, China: A population-based time series study

BACKGROUND

Previous studies have mainly focused on the associations between particulate matters and infant mortality. However, evidence regarding the associations between gaseous pollutants and mortality among children aged <5 years remains sparse.

OBJECTIVES

The aim of this study was to investigate the associations between ambient air pollution and death among children aged <5 years in Beijing, China, and explore the impact of age, gender and specific causes of death on these associations.

METHODS

Concentrations of ambient air pollution and the number of deaths among children aged <5 years in Beijing from January 2014 to September 2016 were extracted from authoritative electronic databases. The associations were estimated for a single-month lag from the current month up to the previous 5 months (lag0-lag5) and moving averages of the current and previous months (lag01-lag05) using generalized additive Poisson regression (adjusted for time trends, season, meteorological variables and holidays). Subgroup analyses related to age, gender and specific diseases were performed. Two-pollutant models were used to evaluate the possible role of single pollutants.

RESULTS

Sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and carbon monoxide (CO) demonstrated the strongest associations with death among children aged <5 years at lag0, and the estimates decreased or even turned negative with the increasing lag periods. For an interquartile range increase in SO₂, NO₂ and CO at lag0, the odds ratios (OR) were 1.332 (95% CI 1.152-1.539), 1.383 (95% CI 1.113-1.718) and 1.273 (95% CI 1.028-1.575). However, CO lost significance after adjusting for SO₂ and NO₂, and PM_2.5 gained significance (OR 1.548, 95% CI 1.061-2.258) after adjusting for PM₁₀. The ORs for SO₂ and NO₂ remained the most stable across all two-pollutant models. The associations for children aged 1-5 years were stronger than those reported for infants at lag0 but lower at the other lag months. The pollutant associations were stronger for congenital heart disease-related death than overall and pneumonia-related death. We did not find significant differences in terms of gender.

CONCLUSION

Exposure to air pollution may increase the incidence of death among children aged <5 years. SO₂ and NO₂ may be the most stable pollutants reflecting associations between air pollution and death, deserving further attention. Children with congenital heart diseases are more susceptible to air pollution. Therefore, it is urgent to implement the clean air targets established by WHO and reduce the exposure of children to air pollution.

Prenatal and early life exposures to ambient air pollution and development

BACKGROUND

Residential proximity to major roadways, and prenatal exposures to particulate matter <2.5 μm (PM_2.5) and ozone (O₃) are linked to poor fetal outcomes but their relationship with childhood development is unclear.

OBJECTIVES

We investigated whether proximity to major roadways, or prenatal and early-life exposures to PM_2.5 and O₃ increase the risk of early developmental delays.

STUDY DESIGN

Prospective cohort.

SETTINGS

New York State excluding New York City.

PARTICIPANTS

4089 singletons and 1016 twins born between 2008 and 2010.

EXPOSURES

Proximity to major roadway was calculated using road network data from the NY Department of Transportation. Concentrations of PM_2.5 and O₃ estimated by the Environmental Protection Agency Downscaler models were spatiotemporally linked to each child's prenatal and early-life addresses incorporating residential history, and locations of maternal work and day-care.

OUTCOMES

Parents reported their children's development at ages 8, 12, 18, 24, 30 and 36 months in five domains using the Ages and Stages Questionnaire. Generalized mixed models estimated the relative risk (RR) and 95% CI for failing any developmental domain per 10 units increase in PM_2.5 and O₃, and for those living <1000 m away from a major roadway compared to those living further. Models adjusted for potential confounders.

RESULTS

Compared to those >1000 m away from a major roadway, those resided 50-100 m [RR: 2.12 (1.00-4.52)] and 100-500 m [RR: 2.07 (1.02-4.22)] away had twice the risk of failing the communication domain. Prenatal exposures to both PM_2.5 and ozone during various pregnancy windows had weak but significant associations with failing any developmental domain with effects ranging from 1.6% to 2.7% for a 10 μg/m³ increase in PM_2.5 and 0.7%-1.7% for a 10 ppb increase in ozone. Average daily postnatal ozone exposure was positively associated with failing the overall screening by 8 months [3.3% (1.1%-5.5%)], 12 months [17.7% (10.4%-25.5%)], and 30 months [7.6%, (1.3%-14.3%)]. Findings were mixed for postnatal PM_2.5 exposures.

CONCLUSIONS

In this prospective cohort study, proximity to major roadway and prenatal/early-life exposures to PM_2.5 and O₃ were associated with developmental delays. While awaiting larger studies with personal air pollution assessment, efforts to minimize air pollution exposures during critical developmental windows may be warranted.

Welding Fume Exposure and Epigenetic Alterations: A Systematic Review

Epigenetics are heritable changes in gene expression not coded in the DNA sequence, which stand at the interface between the genome, environmental exposure and development. From an occupational health perspective, epigenetic variants may link workplace exposures and health effects. Therefore, this review aimed to overview possible epigenetic effects induced by welding fumes on exposed workers and health implications. A systematic search was performed on Pubmed, Scopus, and ISI Web of Knowledge databases. DNA methylation changes have been reported in genes responsible for the cardiac autonomic function and coagulation, i.e., LINE-1, GPR133 and F2RL3, in mitochondrial-DNA-sequences involved in the regulation of energy-generation/redox-signaling, as well as in inflammatory activated genes, i.e., iNOS. However, the limited number of retrieved articles, their cross-sectional nature, the lack of a suitable qualitative-quantitative exposure assessment, and the heterogeneity of biological-outcomes investigated, prevent the extrapolation of a definite causal relationship between welding fumes and epigenetic phenomena. Future studies should clarify the function of such epigenetic alterations as possible markers of occupational exposure and early effect, dose-response relationships, and underlying molecular mechanisms. Overall, this may be helpful to guide suitable risk assessment and management strategies to protect the health of workers exposed to welding fumes.

Neighborhood air pollution and household environmental health as it relates to respiratory health and healthcare utilization among elderly persons with asthma

Objective: The study investigated the associations between fine particulate matter (PM_2.5; <2.5 μm in diameter), indoor environment, pulmonary function, and healthcare utilization in a vulnerable group of elderly persons with asthma. We hypothesized that environmental conditions were associated with adverse pulmonary health outcomes. Methods: The study involved elderly (n = 76; mean age 64.6 years; 48 women) vulnerable persons in Detroit, Michigan, USA, with physician-diagnosed asthma. Exposure variables included measured outdoor PM_2.5, self-rated outdoor and household environmental pollutants. Outcome variables were self-rated and measured pulmonary function, and asthma-related healthcare utilization. Results: Mean ambient PM_2.5 concentrations during the study was 14.14 ± (S.D. 6.36) µg/m³ during the summer and 14.20 (6.33) during the winter (p = 0.95). In multiple regression analyses, adjusting for age and gender, mean 6-month concentration of PM_2.5 was related to shortness of breath (SHOB; standardized β = 0.26, p = 0.02) and inversely with self-rated respiratory health (SRRH; β = 0.28, p = 0.02). However, PM_2.5 did not predict lung function (FEV₁% predicted and FEV₁/FVC). However, PM_2.5 was related to use of asthma controller drugs (β = 0.38, p = 0.001). Participants' air pollution ratings predicted total healthcare utilization (β = 0.33, p = 0.01). Conclusions: In elderly persons with asthma, living near heavy industry and busy highways, objective and perceived environmental pollution relate to participants' respiratory health and healthcare utilization. Importantly, air pollution might increase use of asthma controller drugs containing corticosteroids with implication for elderly persons' risk to develop osteoporosis and cardiovascular disease.

Is smaller worse? New insights about associations of PM1 and respiratory health in children and adolescents

BACKGROUND AND OBJECTIVES

Little is known about PM₁ effects on respiratory health, relative to larger size fractions (PM_2.5). To address this literature gap, we assessed associations between PM₁ exposure and asthmatic symptoms in Chinese children and adolescents, compared with PM_2.5.

METHODS

A total of 59,754 children, aged 2-17 years, were recruited from 94 kindergartens, elementary and middle schools in the Seven Northeast Cities (SNEC) study, during 2012-2013. We obtained information on asthma and asthma-related symptoms including wheeze, persistent phlegm, and persistent cough using a standardized questionnaire developed by the American Thoracic Society. PM₁ and PM_2.5 concentrations were estimated using a spatial statistical model matched to the children's geocoded home addresses. To examine the associations, mixed models with school/kindergarten as random intercept were used, controlling for covariates.

RESULTS

Odds ratios (ORs) of doctor-diagnosed asthma associated with a 10-μg/m³ increase for PM₁ and PM_2.5 were 1.56 (95% CI: 1.46-1.66) and 1.50 (1.41-1.59), respectively, and similar pattern were observed for other outcomes. Interaction analyses indicated that boys and the individuals with an allergic predisposition may be vulnerable subgroups. For example, among children with allergic predisposition, the ORs for doctor diagnosed asthma per 10 μg/m³ increase in PM₁ was 1.71 (95% CI: 1.60-1.83), which was stronger than in their counterparts (1.46; 1.37-1.56) (p_{for interaction} < 0.05).

CONCLUSIONS

This study indicated that long-term exposure to PM₁ may increase the risk of asthma and asthma-related symptoms, especially among boys and those with allergic predisposition. Furthermore, these positive associations for PM₁ were very similar to those for PM_2.5.

Feet in danger: short exposure to contaminated soil causing health damage-an experimental study

In this study, hematological and behavioral changes in Wistar rats exposed to soil collected from urban areas next to an industrial complex were investigated. Animals were exposed to soil samples placed at the bottom of cages for 4 days. After this period, behavioral parameters were measured by the open field test and the elevated plus-maze. Blood was collected to measure hematological parameters. The soil from the vicinity of the oil refining industry caused changes in hematological parameters and altered behavioral parameters in both tests. The soil from the vicinity of the petroleum refining industry and fertilizer industries increased the density of white blood cells and decreased exploratory activity in the exposed animals. The results demonstrate that contact with contaminated soils, even for short periods, can cause physiological damage in organisms and that special attention should be given to people who live under constant exposure to these soils.