Evolution of sperm quality in men living in the vicinity of a municipal solid waste incinerator possibly correlated with decreasing dioxins emission levels

摘要

The objective was to examine the impact on sperm parameters of environmental exposure to dioxins around a municipal waste incinerator initially with high emission levels and during reduction levels. An ecological study with quasi-experimental conditions was performed in patients of a reproductive laboratory. The first semen analyses of 251 men living in Besancon, France, between 2001 and 2007, were included. To analyse the contribution of direct exposure (inhalation), the calendar time was dichotomised in two periods 2001-2003 versus 2004-2007 and used as a proxy for exposure. Regarding the indirect exposure pathway (food), the statistical analysis was made with a nonparametric test to assess the trends. There was a negative correlation between the year of exposure and the percentage of abnormal mid-piece and the multiple abnormalities index, even after adjusting for age and days abstention from intercourse. A positive correlation was found between the progressive motile sperm count and the period of exposure. These findings are to be put into the context of a drastic reduction in emissions of dioxins. Our results suggest an effect of chronic exposure to dioxins on spermiogenesis with more abnormalities. These results should be confirmed with concentration measurements of dioxins in infertile men.