Genetic polymorphisms influence the susceptibility of men to sperm DNA damage associated with exposure to air pollution.

The purpose of the present study was to investigate the impact of carcinogenic polycyclic aromatic hydrocarbons and volatile organic compounds on sperm quality in a group of city policemen in Prague during a period of increased concentrations of ambient air-pollutants (winter season) compared to a period of low exposure (spring). Polymorphisms in metabolic genes (CYP1A1, EPHX1, GSTM1, GSTP1, GSTT1), folic acid metabolism genes (MTR, MTHFR) and DNA repair genes (XRCC1, XPD6, XPD23, hOGG1) were evaluated in these men as potential modifiers of associations between air pollution exposure and changes in sperm quality. The study population was a group of 47 policemen working in the center of the city. Seasonal differences in exposure were verified by ambient and personal monitoring. Markers of sperm injury included semen volume, sperm concentration, sperm morphology, sperm motility, and sperm DNA damage measured with the sperm chromatin structure assay The sperm chromatin structure assay (SCSA) includes a measure of DNA damage called DNA Fragmentation Index (DFI). The % of cells with detectable DFI (detDFI) by this assay includes sperm with either medium or high DNA damage; the term hDFI is used to define the % of sperm with only high DNA damage. The assay also detects immature sperm defined by high density staining (HDS). No significant differences were found in any of the standard semen parameters between the sampling periods except for vitality of sperms. Both DFI and HDS were significantly higher in winter than in spring samples for all men and for non-smokers. At the bivariate level, significant associations between hDFI or detDFI and polymorphisms of the repair genes XRCC1, XPD6 and XPD23 were observed. In multivariate models, polymorphisms of the genes XPD6, XPD23 and CYP1A1MspI were associated with hDFI and HDS. Moreover, HDS was significantly associated with polymorphisms in GSTM1 gene.

The impact of air pollution on the levels of micronuclei measured by automated image analysis.

The measurement of micronuclei (MN) in human peripheral blood lymphocytes is frequently used in molecular epidemiology as one of the preferred methods for assessing chromosomal damage resulting from environmental mutagen exposure. In the present study, we evaluated the effect of exposure to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs), volatile organic compounds (VOC) and smoking on the frequency of MN in a group of 56 city policemen living and working in Prague. The average age of the participants was 34+/-6 years. The study was conducted on the same subjects in February and May 2007. The concentrations of air pollutants were obtained from personal and stationary monitoring. A statistically significant decrease in the levels of pollutants was observed in May when compared with February, with the exception of toluene levels measured by stationary monitoring. The frequency of MN was determined by the automatic image scoring (MetaSystems Metafer 4, version 3.2.1) of DAPI-stained slides. The results of the image analysis indicated a significant difference in the frequency of MN (mean levels 7.32+/-3.42 and 4.67+/-2.92, for February and May, respectively). Our study suggests that automatic image analysis of MN is a highly sensitive method for evaluating the effect of c-PAHs and confirms that there are no differences between smokers and nonsmokers. These results demonstrate the ability of c-PAHs to increase MN frequency, even if the exposure to c-PAHs occurred up to 60 days before the collection of biological material. Our work is the first human biomonitoring study focused on the measurement of MN by automated image analysis for assessing chromosomal damage as a result of environmental mutagen exposure.

Biomarkers of air pollution exposure--a study of policemen in Prague.

The effect of exposure to organic compounds adsorbed onto respirable air particles (<2.5microm) on DNA adducts in lymphocytes was studied in a group of non-smoking policemen (N=109, aged 35+/-0.9 years) working in the downtown area of Prague and spending >8h daily outdoors. Personal exposure to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) adsorbed on respirable particles was monitored in each subject for 48h before biological sampling. DNA adducts were analyzed by a (32)P-postlabelling assay, and total DNA adduct levels and B[a]P-like spots were determined. Further biomarkers included cotinine levels in urine to control for exposure to tobacco smoke, plasma levels of vitamins A, E and C and polymorphisms of metabolic genotypes (GSTM1, GSTP1, GSTT1, CYP 1A1-Msp I and Ile/Val, MTHFR, MS), DNA repair genotypes (XRCC1, hOGG1 and XPD exons 6 and 23) and the p53 gene (p53 Msp I and BstU I). All the biomarkers of exposure and effect were analyzed repeatedly during a period of one year at 2-3 month intervals (January, March, June, September 2004) to cover periods with high (winter) and low (summer) levels of air pollution. The highest personal exposure to c-PAHs was found in January (8.1+/-8.8ng/m(3)), while the other three sampling periods exhibited 3-4-fold lower c-PAH exposure. The total DNA adducts were only slightly elevated in January (2.08+/-1.60) compared to March (1.66+/-0.65), June (1.96+/-1.73) and September (1.77+/-1.77). B[a]P-like DNA adducts, however, were significantly higher in January than in the March and June sampling periods (0.26+/-0.14 vs. 0.19+/-0.12 and 0.22+/-0.13, respectively; p<0.0001 and p=0.017) indicating that c-PAH exposure probably plays a crucial role in DNA adduct formation in lymphocytes. No effect of individual metabololic or DNA repair genotypes on DNA adduct levels was observed. However, the combination of two genotypes encoding enzymes metabolizing c-PAHs - CYP 1A1 and GSTM1 - was associated with the levels of total and B[a]P-like DNA adducts under conditions of increased exposure to c-PAHs. Our study suggests that DNA adducts in the lymphocytes of subjects exposed to increased c-PAH levels are an appropriate biomarker of a biologically effective dose, directly indicating whether or not the extent of exposure to these compounds is related to an increased mutagenic and carcinogenic risk.

The effects of exposure to different clastogens on the pattern of chromosomal aberrations detected by FISH whole chromosome painting in occupationally exposed individuals.

The pattern of chromosomal aberrations (CA) was studied by fluorescence in situ hybridization (FISH) technique (whole chromosomes #1 and #4 painting) in workers occupationally exposed to any of the four following conditions: acrylonitrile (ACN), ethyl benzene (EB), carcinogenic polycyclic aromatic hydrocarbons (c-PAHs), and irradiation in nuclear power plants (NPP), respectively. Decrease in the relative frequency of translocations was observed in EB group, and an increase in reciprocal translocations in ACN and NPP-exposed groups. An increase in a relative number of insertions was registered under all four conditions (significant at ACN, EB, c-PAHs, quasisignificant at NPP-exposed groups). Significant differences in the percentage of lymphocytes with aberrations on chromosome #1 (58.8+/-32.7%, versus 73.8+/-33.6% in the controls, P < 0.05), and chromosome #4 (47.0+/-34.1%, versus 29.4+/-32.2%, P < 0.01) were found in workers exposed to ACN. Similarly, a decrease in the proportion of cells with aberration on chromosome #1 (61.0+/-24.0%, versus 73.8+/-33.6%, P < 0.05) and an increase on chromosome #4 (45.6+/-24.6%, versus 29.4+/-32.2%, P < 0.05) were observed in workers exposed to EB. Frequency of aberrant cells (%AB.C.) as well as genomic frequency of translocations (F(G)/100) increased with age (P < 0.001). Aging also increased the percentage of translocations and reciprocal translocations (P < 0.05), but decreased the relative number of acentric fragments (P < 0.01). Smoking led to significantly increased F(G)/100 (P < 0.05), but did not affect the pattern of chromosomal aberrations. Our results seem to indicate that different carcinogens may induce a different pattern of chromosomal aberrations.

[Maternal exposure to dust particles during pregnancy and fetal growth in 2 regions with different levels of air pollution]. / Expozice matky prachovým cásticím tehotenství a rust plodu ve dvou regionech s rozdílnou úrovní znecisteného ovzdusí.

BACKGROUND: Recently, an association between adverse pregnancy outcome and air pollution was hypothesized in several papers. The aim of the present study is to evaluate the impact of particles with aerodynamic diameter < or = 10 microns (PM10) on the intrauterine growth retardation (IUGR) in two regions with the different levels of air pollution. METHODS AND RESULTS: The study group includes all singleton full term births of European origin over a two-year period in the district of Teplice (n = 1,943) and Prachatice (n = 883). Information on reproductive and health history and lifestyle was obtained from maternal questionnaires and medical records. IUGR was chosen as the indicator of reproductive effects. The mean concentration of PM10 for each women in particular gestational month was calculated. Three concentration intervals were constructed (low < 40 micrograms/m3; medium 40-50 micrograms/m3; high > or = 50 micrograms/m3). Relative risk of IUGR was estimated for particular month and pollutant level. Influence of the potential confounders (maternal age, height and pre-pregnancy weight, smoking, season and the year of study) was controlled using logistic regression models; adjusted odd's ratio (AOR) was estimated. Relative risk of IUGR in Teplice District was increased for medium PM10 levels (AOR = 1.62 CI: 1.07-2.46) (P < 0.02) as well as for high levels in the first gestational month (2.64 CI: 1.48-4.71) (P < 0.001). The same association was observed also in Prachatice District, though the PM10 did not achieve the "high" levels (> or = 50 micrograms/m3). AOR for IUGR for mothers exposed in the 1st gestational month to medium PM10 levels was three times the risk of those exposed to low levels (3.50 CI: 1.82-6.81) (P < 0.0003). No similar relationship was observed in any other gestational stage. CONCLUSIONS: Influence of particles or other associated air pollutants on fetal growth in early gestation is one of several possible explanations of these results. Timing of this effect in both different regions is compatible with a current hypothesis of IUGR etio-pathogenesis. Seasonal factors, one of the other possible explanations, is less probable. More investigation is required to evaluate a possible causal nature of the relationship observed.

Fecundability and parental exposure to ambient sulfur dioxide.

Recently it has been observed that birth rates in Teplice, a highly polluted district in Northern Bohemia, have been reduced during periods when sulfur dioxide levels were high. This study, which is based on data from 2,585 parental pairs in the same region, describes an analysis of the impact of SO(2) on fecundability in the first unprotected menstrual cycle (FUMC). We obtained detailed personal data, including time-to-pregnancy information, via maternal questionnaires at delivery. We estimated individual exposures to SO(2) in each of the 4 months before conception on the basis of continual central monitoring. Three concentration intervals were introduced: < 40 microg/m(3 )(reference level); 40-80 microg/m(3); and [greater than or equal to] 80 microg/m(3). We estimated adjusted odds ratios (AORs) of conception in the FUMC using logistic regression models. Many variables were screened for confounding. AORs for conception in the FUMC were consistently reduced only for couples exposed in the second month before conception to SO(2) levels as follows: 40-80 microg/m(3), AOR 0.57 [95% confidence interval (CI), 0.37-0.88; p < 0.011]; [greater than or equal to] 80 microg/m(3), AOR 0.49 (CI, 0.29-0.81; p < 0.006). The association was weaker in the second 2 years of the study, probably due to the gradual decrease of SO(2) levels in the region. The relationship between SO(2) and fecundability was greater in couples living close to the central monitoring station (within 3.5 km). The timing of these effects is consistent with the period of sperm maturation. This is in agreement with recent findings; sperm abnormalities originating during spermatid maturation were found in young men from Teplice region who were exposed to the increased levels of ambient SO(2). Alternative explanations of our results are also possible.

The impact of polycyclic aromatic hydrocarbons and fine particles on pregnancy outcome.

The relationship between intrauterine growth retardation (IUGR) and exposure to particulate matter [less than/equal to] 10 microm (PM(10)) and particulate matter [less than and equal to] 2.5 microm (PM(2.5))( )in early pregnancy was recently studied in the highly polluted district of Teplice (Northern Bohemia). From this observation rose the question about the possible role of the carcinogenic fraction of polycyclic aromatic hydrocarbons (c-PAHs), which are usually bound to fine particles. The impact of c-PAHs and fine particles on IUGR was analyzed in Teplice and in Prachatice, a region with similarly high c-PAH but low particle levels. All European, single live births occurring in a 4-year period in Teplice (n = 3,378) and Prachatice (n = 1,505) were included. Detailed personal data were obtained via questionnaires and medical records. Mean PM(10), PM(2.5,) and c-PAHs levels during the 9 gestational months (GM) were estimated for each mother. Adjusted odds ratios (AORs) of IUGR for three levels of c-PAHs (low, medium, and high) and for continuous data were estimated after adjustment for a range of covariates using logistic regression models. In the present 4-year sample from Teplice, previously published results about increasing IUGR risk after exposure to particles in the first GM were fully confirmed, but no such effects were found in Prachatice. The AOR of IUGR for fetuses from Teplice exposed to medium levels of c-PAHs in the first GM was 1.60 [confidence interval (CI), 1.06-2. 15], and to high levels 2.15 (CI, 27-3.63). An exposure-response relationship was established by analyzing the continuous data. For each 10 ng increase of c-PAHs in the first GM, the AOR was 1.22 (CI, 1.07-1.39). About the same relationship was observed in Prachatice in spite of the low particle levels. The results prove that exposure to c-PAHs in early gestation may influence fetal growth. The particulate matter-IUGR association observed earlier may be at least partly explained by the presence of c-PAHs on particle surfaces.

Fetal growth and maternal exposure to particulate matter during pregnancy.

Prior studies reported an association between ambient air concentrations of total suspended particles and SO2 during pregnancy and adverse pregnancy outcomes. We examined the possible impact of particulate matter up to 10 microm (PM10) and up to 2.5 microm (PM2. 5) in size on intrauterine growth retardation (IUGR) risk in a highly polluted area of Northern Bohemia (Teplice District). The study group includes all singleton full-term births of European origin over a 2-year period in the Teplice District. Information on reproductive history, health, and lifestyle was obtained from maternal questionnaires. The mean concentrations of pollutants for each month of gestation were calculated using continuous monitoring data. Three intervals (low, medium, and high) were constructed for each pollutant (tertiles). Odds ratios (ORs) for IUGR for PM10 and PM2.5 levels were generated using logistic regression for each month of gestation after adjustment for potential confounding factors. Adjusted ORs for IUGR related to ambient PM10 levels in the first gestational month increased along the concentration intervals: medium 1.62 [95% confidence interval (CI), 1.07-2.46], high 2.64 (CI, 1.48-4.71). ORs for PM2.5 were 1.26 (CI, 0.81-1.95) and 2.11 (CI, 1. 20-3.70), respectively. No other associations of IUGR risk with particulate matter were found. Influence of particles or other associated air pollutants on fetal growth in early gestation is one of several possible explanations of these results. Timing of this effect is compatible with a current hypothesis of IUGR pathogenesis. Seasonal factors, one of the other possible explanations, is less probable. More investigation is required to examine these findings and alternative explanations.