Early biological effects in outdoor workers exposed to urban air pollution: A systematic review

Urban outdoor workers (OWs), identified as professionals spending most of their working shifts in an urban environment, are exposed for at least 8 h/day to traffic air pollution, leading to potential health risks. This paper reports the results of a systematic review aimed at identifying the potential health outcomes of exposure to air pollutants for OWs, focusing mainly on police officers, drivers and street vendors. Health outcomes were analysed in terms of early biological effects quantified with specific measured indicators. The main inclusion criterion was the assessment of at least one early biological effect (genetic and epigenetic damage/alterations, inflammation or oxidative stress indicators, or hormonal imbalance) in a population of OWs exposed to urban air pollution. By applying the PRISMA workflow, 82 papers were included in this study. The results showed that the measured pollutant concentrations were significantly below the current occupational limit values, while exceeds the indications of WHO for urban air pollution. This exposure led to significant alterations of biological markers in OWs with respect to non-exposed subjects. In particular, OWs presented an increased frequency of micronuclei and DNA adducts as the main DNA alterations, while police officers (a category of highly exposed OWs) showed hormonal alterations affecting mainly the hypothalamic-pituitary-gonadal axis. Concerning oxidative stress and inflammation, all the analysed matrices (i.e. blood, sputum, urine and lachrymal fluids) showed increased indices for OWs respect to non-exposed groups. Therefore, the evaluation of effect biomarkers to detect early alterations provides crucial information for supporting the occupational risk management of OWs and, at broader level, allows for an insight of the early-stage health outcomes due to urban air pollution.

Association between ambient air pollution and blood sex hormones levels in men

Concerns are growing over time on the adverse health effects of air pollution. However, the association between ambient air pollution and blood sex hormones in men is poorly understood. We included 72,917 men aged 20-55 years from February 2014 to December 2019 in Beijing, China in this study. Blood testosterone, follicle stimulating hormone, luteinizing hormone, estradiol, and prolactin levels of each participant were measured. We collected exposure data of daily ambient levels of particulate matter ≤10 μm (PM₁₀) and ≤2.5 μm (PM_2.5), nitrogen dioxide, sulfur dioxide (SO₂), carbon monoxide, and ozone. Generalized linear mixed models were used to analyze the potential association between ambient air pollution exposure and blood sex hormone levels. The results showed that both immediate and short-term cumulative PM_2.5, PM₁₀, and SO₂ exposure was related to altered serum sex hormone levels in men, especially testosterone. An increase of 10 μg/m³ in PM_2.5 and PM₁₀ in the current day was related to a 1.6% (95% confidence interval [CI]: 0.9%-2.3%) and 1.1% (95% CI: 0.5%-1.6%) decrease in testosterone, respectively, and a decreasing tendency of accumulated effects persisted within lag 0-30 days. The present study demonstrated that it is important to control ambient air pollution exposure to reduce effects on the reproductive health of men.

Exposure to ambient air pollution--does it affect semen quality and the level of reproductive hormones?

BACKGROUND

Ambient air pollution has been associated with a variety of reproductive disorders. However, a limited amount of research has been conducted to examine the association between air pollution and male reproductive outcomes, specifically semen quality.

AIM

The present study was designed to address the hypothesis that exposure to fluctuating levels of specific air pollutants adversely affects sperm parameters and the level of reproductive hormones.

SUBJECTS AND METHODS

The study population consisted of 327 men who were attending an infertility clinic in Łodź, Poland for diagnostic purposes and who had normal semen concentration of 15-300 mln/ml. All participants were interviewed and provided a semen sample. Air quality data were obtained from AirBase database.

RESULTS

The statistically significant association was observed between abnormalities in sperm morphology and exposure to all examined air pollutants (PM10, PM2.5, SO2, NOX, CO). Exposure to air pollutants (PM10, PM2.5, CO, NOx) was also negatively associated with the level of testosterone. Additional exposure to PM2.5, PM10 increase the percentage of cells with immature chromatin (HDS).

CONCLUSIONS

The present study provides suggestive evidence of an association between ambient air pollution and sperm quality. Further research is needed to explore this association in more detail. Individual precise exposure assessment would be needed for more detailed risk characterization.

Plasma cortisol concentrations and lifestyle in a population of outdoor workers

The aim of this study was to assess whether exposure to urban pollution in outdoor workers, may alter plasma cortisol concentrations also in relation to the effect of smoking and drinking habits. The research was carried out on 498 outdoor police workers, divided into three groups; Group A: traffic policemen (TP), Group B: drivers (D), Group C: Other duties (OD). To evaluate separately the effect of using alcohol and smoking, each group was divided into three subgroups: (1) non-smokers and non-drinkers, (2) smokers and non-drinkers, (3) non-smokers and drinkers. Our results show cortisol mean values were significantly higher in the TP group compared to the D and OD groups without significant differences between the last two groups. The results suggest that exposure to pollutants associated with urban psychosocial stress may play a more important role on plasma cortisol levels than smoking and alcohol.