In research published (Wednesday 30 April) in Europe's leading reproductive medicine journal Human Reproduction the research team from the University of Naples say their work should prompt studies on other types of workers exposed to similar levels of pollution and alert health authorities to pollution's insidious health effects.
Dr Michele De Rosa and colleagues examined semen quality in 85 men employed at motorway tollgates and 85 aged-matched controls living in the same area.
Although they found that sperm counts and serum levels of FSH (follicle stimulating hormone), LH (luteinizing hormone) and testosterone were within the normal range in both groups, all other sperm parameters were deranged and below World Health Organisation levels in the tollgate workers. The tollgate workers had significantly lower total sperm motility (movement) including forward progression and significantly lower levels in other tests of sperm kinetics and function.
Said Dr De Rosa: "Environmental levels of occupational pollutants, except carbon dioxide, at the tollgates exceeded the maximum legal levels and the workers were exposed to significantly higher levels of nitrogen oxides, sulphur oxides, carbon monoxide and lead than the controls. Although circulating levels of toxicological markers were within normal range we found significantly higher levels of four particular markers methaemoglobin, sulphaemoglobin, blood Pb (lead) and zinc-protoporphyrin in the tollgate workers."
A range of analyses by the research team identified nitrogen oxides and lead as the most likely culprits damaging the sperm. There was an inverse correlation between sperm count and circulating blood lead levels and other sperm parameters were inversely correlated with the marker for nitrogen oxide levels m
Contact: Margaret Willson
European Society for Human Reproduction and Embryology