Short-term exposure to air pollution might exacerbate autoimmune diseases

The effect of air pollution on systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease resulting from impaired inflammatory responses. Given the role of air pollution on increasing inflammatory mediators, thus, we aimed to systematically review and meta-analyze evidence regarding an association between short-term exposure to air pollution and SLE onset, activity, and hospitalization.

METHODS

Electronic databases including Web of Science, PubMed, Scopus, and Embase were searched for all published articles until July 5, 2021. Newcastle Ottawa Scale (NOS) checklist was used to assess the quality of individual studies. Relevant demographic data and the intended results of the selected studies were extracted, and their adjusted risk ratios (RRs) were pooled using random and fixed effect analysis based on the heterogeneity index.

FINDINGS

Twelve studies were entered in our systematic review, and finally, six publications were enrolled in meta-analysis. Overall, Meta-analysis showed no significant association between an increase of PM_2.5 on the third day and SLEDAI score with pooled adjusted RR of 1.212 (95% CI, 0,853-1.721), p-value = 0.284. However, there was a positive relationship between 6 days increase of Particulate matter (PM) 2.5 and the systemic lupus erythematosus disease activity Index (SLEDAI) score (pooled adjusted RR 1.112; 95% CI, 1.005-1.231), p-value = 0.040. There was no significant association between carbon monoxide (CO), nitrogen dioxide (NO₂), PM_2.5, and PM₁₀ increase in the air and hospitalization of SLE patients with pooled RR of 1.021 (95% CI, 0,986-1.1.057), p-value = 0.249, 1.034 (95% CI, 0.996-1.068); p-value = 0.079, 1.042 (95% CI, 0.994-1.092); p-value = 0.084 and 1.004 (95% CI, 0.996-1.013); p-value = 0.323, respectively. Also, analysis showed a significant relation between ozone (O₃) increase and hospitalization with a pooled RR of 1.076 (95% CI, 1.009-1.147); p-value = 0.025. Finally, analysis of SO₂ increase and risk of hospitalization demonstrated no significant relationship with the pooled RR of 1.011; (95% CI, 0.962-1.062), p-value = 0.0.671.

CONCLUSION

Our findings prove that PM_2.5 was associated with increased SLE risk. We also showed that only O₃ was associated with increased hospital admissions of SLE patients.

Adverse Effects of fine particulate matter on human kidney functioning: a systematic review

BACKGROUND

Ambient fine particulate matter (PM < 2.5 μm, PM2.5) is gaining increasing attention as an environmental risk factor for health. The kidneys are considered a particularly vulnerable target to the toxic effects that PM2.5 exerts. Alteration of kidney function may lead to a disrupted homeostasis, affecting disparate tissues in the body. This review intends to summarize all relevant knowledge published between January 2000 and December 2021 on the effects of ambient PM2.5 and the adverse effects on kidney function in adults (≥ 18 years).

RESULTS AND DISCUSSION

Studies published in peer-reviewed journals, written in English, regarding the effects of PM2.5 on kidney function and the development and/or exacerbation of kidney disease(s) were included. Of the 587 nonduplicate studies evaluated, 40 were included, comprising of studies on healthy or diagnosed with pre-existing disease (sub)populations. Most of the studies were cohort studies (n = 27), followed by 10 cross-sectional, 1 ecological and 2 time-series studies. One longitudinal study was considered intermediate risk of bias, the other included studies were considered low risk of bias. A large portion of the studies (n = 36) showed that PM2.5 exposure worsened kidney outcome(s) investigated; however, some studies show contradictory results. Measurement of the estimated glomerular filtration rate, for instance, was found to be positively associated (n = 8) as well as negatively associated (n = 4) with PM2.5.

LIMITATIONS AND CONCLUSION

The main limitations of the included studies include residual confounding (e.g., smoking) and lack of individual exposure levels. The majority of included studies focused on specific subpopulations, which may limit generalizability. Evidence of the detrimental effects that ambient PM2.5 may exert on kidney function is emerging. However, further investigations are required to determine how and to what extent air pollution, specifically PM2.5, exerts adverse effects on the kidney and alters its function.

REGISTRATION

The systematic review protocol was submitted and published by the International Prospective Register of Systematic Reviews (PROSPERO; CRD42020175615 ).

Association between ambient air pollution and multiple sclerosis: a systemic review and meta-analysis

Recently, increasing attention has been paid to the effects of air pollutants on autoimmune diseases. The results of relationship between ambient air pollution and multiple sclerosis (MS) showed a variety of differences. Thus, the purpose of this study is to further clarify and quantify the relationship between ambient air pollutants and MS through meta-analysis. Through electronic literature search, literature related to our research topic was collected in Cochrane Library, Embase, and PubMed till August 18, 2020, according to certain criteria. Pooled risk estimate and 95% confidence intervals (95%CI) were calculated by random-effect model analysis. After removing copies, browsing titles and abstracts, and reading full text, 6 studies were finally included. The results showed that only particulate matter (PM) with aerodynamic diameter ≤ 10 (PM₁₀) was related to MS (pooled HR = 1.058, 95% CI = 1.050-1.066), and no correlation was found between PM with aerodynamic diameter < 2.5 (PM_2.5), nitrogen dioxide (NO₂), carbon monoxide (CO), ozone (O₃), benzene (C₆H₆), major road < 50 m, and MS. There was no publication bias, and the heterogeneity analysis results were stable. PM₁₀ is correlated with the disease MS, while other pollution is not connected with MS. Therefore, it is important for MS patients to take personal protection against particulate pollution and avoid exposure to higher levels of PM.

The association between air pollution and hospitalization for patients with systemic lupus erythematosus in Chile: A daily time series analysis

Genetic and environmental factors are thought to influence the activity of systemic lupus erythematosus (SLE), but relatively little is known about the effects of ambient air pollution. Using pollution data from air monitoring stations in the urban centers in Santiago Chile, along with daily patient hospitalization data from 2001 to 2012, an association between ambient air pollution and daily hospital admissions for SLE was tested using generalized linear models. Averaged over all regions pollutant mean 24 h concentrations were: 0.96 ppm carbon monoxide (CO), 64 ppb ozone (O₃), 43 ppb nitrogen dioxide (NO₂), 9 ppb sulphur dioxide (SO₂), 29 μg/m³ particulate matter ≤ 2.5 μm in mean aerodynamic diameter (PM_2.5), and 67 μg/m³ particulate matter ≤ 10 μm in diameter (PM₁₀). The relative risk estimates in single pollutant models for an interquartile range (IQR) increase in pollutant were: RR = 1.34 (95% CI: 1.06-1.83) for SO₂, RR = 1.60 (95% CI: 1.15-2.24) for CO, and RR = 1.41 (95% CI: 1.14-1.86) for PM_2.5. In two-pollutant models, the significance of SO₂ and PM_2.5 persisted despite adjustments for each of the other measured pollutants. These findings suggest that acute increases in air pollution increase the risk of hospitalization with a primary diagnosis of SLE.

Health Impact of Silver Nanoparticles: A Review of the Biodistribution and Toxicity Following Various Routes of Exposure

Engineered nanomaterials (ENMs) have gained huge importance in technological advancements over the past few years. Among the various ENMs, silver nanoparticles (AgNPs) have become one of the most explored nanotechnology-derived nanostructures and have been intensively investigated for their unique physicochemical properties. The widespread commercial and biomedical application of nanosilver include its use as a catalyst and an optical receptor in cosmetics, electronics and textile engineering, as a bactericidal agent, and in wound dressings, surgical instruments, and disinfectants. This, in turn, has increased the potential for interactions of AgNPs with terrestrial and aquatic environments, as well as potential exposure and toxicity to human health. In the present review, after giving an overview of ENMs, we discuss the current advances on the physiochemical properties of AgNPs with specific emphasis on biodistribution and both in vitro and in vivo toxicity following various routes of exposure. Most in vitro studies have demonstrated the size-, dose- and coating-dependent cellular uptake of AgNPs. Following NPs exposure, in vivo biodistribution studies have reported Ag accumulation and toxicity to local as well as distant organs. Though there has been an increase in the number of studies in this area, more investigations are required to understand the mechanisms of toxicity following various modes of exposure to AgNPs.