Semen Quality and Reproductive Health of Young Czech Men Exposed to Seasonal Air Pollution
Selevan, Sherry G., Borkovec, Libor, Slott, Valerie L., Zudova, Zdena, Rubes, Jiri, Evenson, Donald P., Perreault, Sally D., Environmental Health Perspectives
This study of male reproductive health in the Czech Republic resulted from community concern about potential adverse effects of air pollution. We compared young men (18 years of age) living in Teplice, a highly industrialized district with seasonally elevated levels of air pollution, to those from Prachatice, a rural district with relatively clean air. Surveys were scheduled for either late winter, after the season of higher air pollution, or at the end of summer, when pollution was low. Participation included a physical examination, donation of a semen sample, and completion of a questionnaire on health, personal habits, and exposure to solvents and metals through work or hobby. Analysis of data from 408 volunteers showed that the men from Teplice and Prachatice were similar in physical characteristics, personal habits, and work- or hobby-related exposures. Sixty-six percent (272) of these men donated a single semen sample for routine semen analysis, computer-aided sperm motion analysis, and sperm chromatin structure assay. The mean (median) sperm concentration and sperm count were 61.2 (44.0) million/mL semen and 113.3 (81.5) million, respectively, and were not associated with district of residence or period of elevated air pollution. However, periods of elevated air pollution in Teplice were significantly associated with decrements in other semen measures including proportionately fewer motile sperm, proportionately fewer sperm with normal morphology or normal head shape, and proportionately more sperm with abnormal chromatin. These results suggest that young men may experience alterations in sperm quality after exposure to periods of elevated air pollution, without changes in sperm numbers. Key words, air pollution, epidemiology, human, semen, sperm chromatin, sperm count, sperm morphology, sperm motility. Environ Health Perspect 108:887-894 (2000). [Online 2 August 2000]
Air pollution in the Czech Republic increased dramatically with the advent of industrialization in the 1950s, primarily the result of increasing use of brown coal (with high sulfur content) for both home heating and industry. Sulfur dioxide emissions in Czechoslovakia amounted to 0.9 million tons in the 1950s and increased to 3.5 million tons by 1985 (1). This increase was particularly pronounced in the mountainous region of Northern Bohemia, where coal comes from mammoth open-pit mines and is used to heat homes and generate power for local industry. During the 1980s, ambient [SO.sub.2] levels associated with high levels of particulate matter (PM) in the Teplice district of Northern Bohemia frequently exceeded U.S. and Czech air pollution standards (2,3) in winter, when the use of coal increases and thermal inversions favor retention of the air pollution in the valley (4).
The Teplice Program, an international research program, was initiated in 1991 in response to concerns over potential health effects of this pollution. This program sponsored cooperative research among the Czech Institute of Hygiene, the Czech Ministry of the Environment, and the U.S. Environmental Protection Agency to compare health status in Teplice district to that in Prachatice district (5). We chose Prachatice because of its relatively cleaner air. A critical component of this program was the establishment of air monitoring in both districts to measure aerosol and gas-phase air pollutants [PM, including volatile and semivolatile polycyclic aromatic hydrocarbons (PAHs) and toxic metals] as well as [SO.sub.2], nitrous oxides ([NO.sub.x]), and carbon monoxide on an ongoing basis. Monitoring confirmed that levels of these air pollutants were considerably higher in Teplice than in Prachatice, and were higher in the winter than during the rest of the year in both districts (5,6). The Teplice Program includes studies of a number of health outcomes, including respiratory and neurologic effects in children, biomonitoring of mutagens in adults, and reproductive health in pregnant women and young men (5). …