ABSTRACT
Previous studies suggest that air pollution has a negative effect on semen quality. However, most studies are cross-sectional and the results are controversial. This study investigated the associations between air pollutants (PM2.5, PM10, SO2, NO2, CO, and O3) and semen quality among sperm donation candidates, especially when the air pollution was artificially controlled in Beijing, China. We analyzed 8945 semen samples in the human sperm bank of Peking University Third Hospital (Beijing, China) from October 2015 to May 2018. Air pollution data during the entire period (0-90 days prior) and key stages (0-9, 10-14, and 70-90 days prior) of sperm development were collected from the China National Environmental Monitoring Centre. The association between air pollutants and semen parameters (sperm concentration and progressive motility) was analyzed by a mixed model adjusted for age, abstinence duration, month, and average ambient temperature. Only O3 during key stages of 0-9 days and 10-14 days and the entire period was negatively associated with sperm concentration between 2015 and 2018 (P 0.01). During the period of air pollution control from November 2017 to January 2018, except for the increase in O3 concentration, other five pollutants' concentrations decreased compared to those in previous years. In this period, the sperm concentration decreased (P 0.001). During the pollution-control period, O3 exposure 10-14 days prior was negatively associated with sperm concentration (95% CI: -0.399--0.111; P 0.001). No significant association was found between the other five pollutants and semen quality during that period. Our study suggested that only O3 exposure was harmful to semen quality. Therefore, O3 should not be neglected during pollution control operation.
ABSTRACT
Aims: To determine the lung function of cleaners exposed to particulate matter of aerodynamic diameter less than 2.5 micrometer (PM2.5) in the streets and offices in Lusaka, Zambia. Study Design: This was a cross sectional study between two groups. Place and Duration of Study: Lusaka city, central business area, between June and August 2014. Methodology: The study included women between 18-50 years of age who had been working as street or office cleaners for 6 months or more. Males and individuals in both groups who used to smoke or were currently smokers, as well as those with a history of respiratory related illnesses or had cardiopulmonary conditions were excluded from the study. The cleaners were interviewed to get information on socio-demographic characteristics and other information using a structured interview schedule. The participants’ lung volumes, forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and their ratio (FEV1/FVC) were measured using a MRI spirobank G spirometer. On the day of the interview, PM2.5 in their work environment was sampled using a personal aerosol monitor (SIDEPAK AM510). Results: Out of the 90 participants, 45 were street sweepers and 45 were office cleaners. More street sweepers had impaired lung function (FEV1/FVC) 15(75%) than office cleaners 5(25%) p=0.01. FEV1 was also significantly different among street sweepers 12(70.6%) and office cleaners 5(29.4%) p=0.05. PM2.5 measurements revealed significantly high levels of exposure among street sweepers (p=0.001). Participants with impaired lung function (p=.005) and those with reduced FEV1percent predicted were exposed to significantly high concentrations of PM2.5 (p=0.012). Conclusion: Exposure to high PM2.5 concentration is associated with pulmonary function impairment and reduced FEV1 % predicted among cleaners.