Organophosphorus pesticide exposure decreases sperm quality: association between sperm parameters and urinary pesticide levels

Several studies have suggested that human semen quality has declined over the past decades and some of them have associated it with occupational exposure to pesticides. However, most of these studies have not been associated with a reliable exposure level and have been designed mostly as cross-sectional studies. The present work evaluates, in a longitudinal follow-up study, the effect of organophosphate pesticides (OP) at three occupational exposure levels on semen quality. In addition, the study examined the association between OP urinary levels and sperm parameters in exposed and unexposed workers. A total of 139 semen samples from 52 volunteers were assessed. Urinary OP levels were measured by gas-liquid chromatography.The results revealed that the poorest semen quality was found among the subjects with the highest OP exposure and the highest urinary OP levels. Seasonal variations in sperm concentration and sperm count were registered.The results showed a significant decrease in total sperm count among subjects with the highest exposure to OP. Further studies assessing the effects of OP on male reproductive health should be controlled by the variability in human sperm parameters, sperm seasonality, spermatogenesis time and the changing OP exposure level in men highly exposed to OP.     

PON1Q192R genetic polymorphism modifies organophosphorous pesticide effects on semen quality and DNA integrity in agricultural workers from southern Mexico

Pesticide exposure, including organophosphorous (OP) insecticides, has been associated with poor semen quality, and paraoxonase (PON1), an enzyme involved in OP deactivation, may have a role on their susceptibility, due to PON1 polymorphisms. Our objective was to evaluate the role of PON1Q192R polymorphism on the susceptibility to OP toxicity on semen quality and DNA integrity in agricultural workers. A cross-sectional study was conducted in farmers with Mayan ascendancy from southeastern Mexico chronically exposed to pesticides; mostly OP. Fifty four agricultural workers (18-55 years old) were included, who provided semen and blood samples. Semen quality was evaluated according to WHO, sperm DNA damage by in situ-nick translation (NT-positive cells), PON1Q192R polymorphism by real-time PCR and serum PON1 activity by using phenylacetate and paraoxon. Two OP exposure indexes were created: at the month of sampling and during 3 months before sampling, representing the exposure to spermatids-spermatozoa and to cells at one spermatogenic cycle, respectively. PON1 192R and 192Q allele frequencies were 0.54 and 0.46, respectively. Significant associations were found between OP exposure at the month of sampling and NT-positive cells and sperm viability in homozygote 192RR subjects, and dose-effect relationships were observed between OP exposure during 3 months before sampling and sperm quality parameters and NT-positive cells in homozygote 192RR farmers. This suggests that cells at all stages of spermatogenesis are target of OP, and that there exists an interaction between OP exposure and PON1Q192R polymorphism on these effects; farmers featuring the 192RR genotype were more susceptible to develop reproductive toxic effects by OP exposure.     

The effects of long-term occupational exposure to carbon disulphide on serum lipids.

No definite conclusion can be made from many epidemiological and clinical studies of lipid metabolism in workers exposed to carbon disulphide (CS2). The aim of our investigation was to study the serum lipid levels in workers exposed to different CS2 levels to establish possible exposure-response relationships. The first group, spinners, were exposed to high CS2 levels; the second group, workers in viscose production, to low CS2 levels; and the third group included non-exposed workers. As a part of a large examination, total and free serum cholesterol, total lipid and triglyceride levels were determined. Mean total lipid levels were similar in high and low CS2 exposed workers, but significantly lower in non-exposed workers. The total serum cholesterol mean levels were also similar in both groups, but significantly higher in the non-exposed group. Only serum triglyceride values were related to the CS2 levels: the most elevated were in the high exposed workers, somewhat lower in the low exposed, and the lowest in the non-exposed group. The finding is especially important as triglycerides are the most specific for developing atherosclerosis, which is often reported in workers with long-term exposure to carbon disulphide.     

No change in serum dopamine-beta-hydroxylase activity in workers exposed to trichloroethylene

To determine whether occupational exposure to trichloroethylene (TCE) influences sympathetic nerve activity, serum dopamine-beta-hydroxylase (DBH) activities were analyzed in 84 male workers exposed to TCE and 83 male age-matched controls. The workers were exposed to about 22 ppm TCE in air. There were no significant differences between the mean serum DBH activity levels for the exposed workers and the corresponding controls. No significant correlation was found between the serum DBH activities and the urinary TCE-metabolite levels or the duration of employment of the workers. The results suggest that chronic occupational exposure to TCE did not influence sympathetic nerve activity of the workers.     

Long-term effects of an organophosphate upon the human electroencephalogram.

The brain electrical activity of workers exposed to the organophosphate compound (OP), sarin, was compared to that of control subjects. Exposed workers had a history of one or more documented accidental exposures to toxic levels of sarin. However, no exposed subject had exposure within 1 year of his examination. The comparison included standard clinical electroencephalograms (EEGs), computer-derived EEG spectral analysis, and standard overnight sleep EEGs. It was not possible to diagnose subjects individually by expert visual inspection of their EEGs. However, statistically significant between-group differences for both the visually inspected and computer-derived data were reported by both univariate and multivariate statistical methods. Different EEG changes revealed by visual inspection and computer-derived spectral analysis appear to reflect the differing sensitivites of these two analytic techniques. Statistically significant group differences included increased beta activity, increased delta and theta slowing, decreased alpha activity, and increased amounts of rapid eye movement sleep in the exposed population. It is suggested that the above findings represent an unexpected persistence of known short-term OP actions. It is also suggested that these results, when taken along with the reported long-term behavioral effects of OP exposure, provide parallel evidence that OP exposure can produce long-term changes in brain function.     

Evaluation of oxidative stress and genotoxicity in organophosphorus insecticide formulators

The aim of this study was to evaluate genotoxicity and oxidative stress in workers who formulate organophosphorus (OP) pesticides. In this survey, blood leukocytes and erythrocytes of a group of 21 pesticide formulating workers and an equal number of control subjects were examined for genotoxicity and oxidative stress parameters. The mean comet tail length and mean comet length were used to measure DNA damage. Lipid peroxidation level, catalase, superoxide dismutase (SOD) and glutathione peroxidase activities in erythrocytes were analysed as biomarkers of oxidative stress. In addition, the acetylcholinesterase activity was measured as a biomarker of toxicity. The average duration of employment of workers in the factory was 97 months. Results indicated that chronic exposure (multiple-dose, greater than or equal to 6 months duration) to OP pesticides was associated with increased activities of catalase, SOD and glutathione peroxidase in erythrocytes. The level of lipid peroxidation and acetylcholinesterase activity did not show any significant differences between the two groups. The results also indicated that chronic exposure to OP pesticides was associated with increased DNA damage. It is concluded that human chronic exposure to OP pesticides may result in stimulated antioxidant enzymes and increased DNA damage in the absence of depressed acetylcholinesterase levels. Routine genotoxicity monitoring concomitant to acetylcholinesterase activity in workers occupationally exposed to OP insecticides is suggested.     

Neuropsychiatric evaluation in subjects chronically exposed to organophosphate pesticides.

Long-term exposure to low levels of organophosphate pesticides (OP) may produce neuropsychiatric symptoms. We performed clinical, neuropsychiatric, and laboratory evaluations of 37 workers involved in family agriculture of tobacco from southern Brazil who had been exposed to OP for 3 months, and in 25 of these workers, after 3 months without exposure to OP. Plasma acetylcholinesterase activity levels of all subjects were within the normal range (3.2 to 9.0 U/l) and were not different between on- and off-exposure periods (4.7 +/- 0.9 and 4.5 +/- 1.1 U/l, respectively). Clinically significant extrapyramidal symptoms were present in 12 of 25 subjects, which is unexpected in such a population. There was a significant reduction of extrapyramidal symptoms after 3 months without exposure to OP, but 10 subjects still had significant parkinsonism. Mini-mental and word span scores were within the expected range for this population and were not influenced by exposure to OP. Eighteen of the 37 subjects (48%) had current psychiatric diagnoses in the first interview (13 with generalized anxiety disorder and 8 with major depression). Among the 25 subjects who completed both evaluations, the total number of current psychiatric diagnoses, after 3 months without using OP, dropped from 24 to 13 and the number of affected individuals with any psychiatric diagnosis dropped from 11 to 7. In conclusion, this study reinforces the need for parameters other than acetylcholinesterase activity to monitor for chronic consequences of chronic low-dose OP exposure, and it suggests that subjects have not only transient motor and psychiatric consequences while exposed, but may also develop enduring extrapyramidal symptoms.     

Health surveillance and biological monitoring of pesticide formulators in India

Results of health survey and biological monitoring in pesticide formulators exposed to a combination of pesticides, an organophosphorus (OP) insecticide (phorate) and a persistent chlorinated insecticide (technical hexachlorocyclohexane; HCH; BHC) are reported. Exposure of 160 workers to a combination of pesticides (malathion, parathion, DDT and HCH) resulted in 73% of the workers showing toxic signs and symptoms. Formulators showed marked inhibition of whole blood, plasma and red blood cell cholinesterase (ChE) activity and slightly higher concentrations of DDT and HCH in serum. An interesting observation was that over 25% of the formulators showed ECG aberrations. The ECG changes were not related to whole blood ChE activity. Exposure to the chlorinated insecticide HCH in 19 workers engaged in the manufacture of technical HCH resulted in toxic signs and symptoms in over 90% of the subjects. The HCH concentrations in serum showed a ten-fold increase. Changes in the liver enzymes ornithine carbamyl transferase (OCT), gamma-glutamyl transpeptidase (GGTP), leucine aminopeptidase (LAP) and in immunoglobulin M(IgM) showed possible effects on liver and humoral immunity. ECG monitoring showed evidence of cardiac effects. Exposure of 40 formulators to a highly toxic OP insecticide (phorate) showed that over 60% of the workers suffered from toxic effects in spite of using a complete set of protective clothing. A marked and progressive inhibition in whole blood and plasma ChE activity was found during the two weeks of exposure to phorate. An appreciable recovery in ChE activity was observed 10 days after cessation of exposure. These surveys have established the need to practice and develop biological monitoring techniques to assess exposure and predict health risks in workers occupationally exposed to pesticides.     

PARAOXONASE AND ACETYLCHOLINESTERASE ACTIVITIES IN HUMANS EXPOSED TO ORGANOPHOSPHOROUS COMPOUNDS

Different kinds of organophosphorous compounds (OP) are used as pesticides in Turkish agriculture. Suicidal, accidental, or occupational exposure may occur in developing countries. OP inhibit acetylcholinesterase (AChE) activities; on the other hand, serum paraoxonase (PON1) hydrolyzes the toxic metabolites of a variety of OP. In recent years, some studies have shown that PON1 activity is an important marker in individuals who are exposed to OP. Both serum cholinesterase and PON1 activities were measured spectrophotometrically from 18 male agricultural workers who were chronically exposed to azinphos methyl, chlorpyriphos, or malathion and other pesticides during cereal spraying, transportation, and storage. The individuals were classified according to PON1 phenotypes using the antimode 60% stimulation method to determine the dividing point between non-salt-stimulated, A type (homozygotes for the low activity allele), and salt-stimulated AB (heterozygotes) and B types (homozygotes for the high-activity allele). A positive correlation was found between AChE activities and percent of PON1 stimulation. The individuals with phenotype A had the lowest enzyme activities. This study suggests that individuals with phenotype A might be more sensitive to OP-induced toxicity.     

Paraoxonase and acetylcholinesterase activities in humans exposed to organophosphorous compounds

Different kinds of organophosphorous compounds (OP) are used as pesticides in Turkish agriculture. Suicidal, accidental, or occupational exposure may occur in developing countries. OP inhibit acetylcholinesterase (AChE) activities; on the other hand, serum paraoxonase (PON1) hydrolyzes the toxic metabolites of a variety of OP. In recent years, some studies have shown that PON1 activity is an important marker in individuals who are exposed to OP. Both serum cholinesterase and PON1 activities were measured spectrophotometrically from 18 male agricultural workers who were chronically exposed to azinphos methyl, chlorpyriphos, or malathion and other pesticides during cereal spraying, transportation, and storage. The individuals were classified according to PON1 phenotypes using the antimode 60% stimulation method to determine the dividing point between non-salt-stimulated, A type (homozygotes for the low-activity allele), and salt-stimulated AB (heterozygotes) and B types (homozygotes for the high-activity allele). A positive correlation was found between AChE activities and percent of PON1 stimulation. The individuals with phenotype A had the lowest enzyme activities. This study suggests that individuals with phenotype A might be more sensitive to OP-induced toxicity.     

Embryonic exposure to octylphenol induces changes in testosterone levels and disrupts reproductive efficiency in rats at their adulthood

The purpose of the present study was to investigate the effects of prenatal exposure to octylphenol (OP) at the dose of 50 mg/kg body weight on days 1, 7 and 14 of pregnancy on reproductive health of male rats at adulthood. F1 male rats from control and OP exposed animals were weaned and maintained up to postnatal day (PND) 100. The indices of testis, epididymis and seminal vesicles were significantly decreased in male rats exposed to OP during embryonic development when compared with controls. Significant reduction in the epididymal sperm count, viable sperms and motile sperms and number of tail coiled sperms (HOS-test) were observed in experimental rats when compared to control rats. The levels of serum testosterone and also activity levels of testicular hydroxysteroid dehydrogenases were significantly decreased with a significant increase in the serum follicle stimulating and leutinizing hormones in experimental rats. Furthermore, embryonic exposure to OP caused significant down regulation of StAR, 3ß hydroxysteroid dehydrogenase and 17ß hydroxysteroid dehydrogenase mRNAs in testis of adult rats as compared to control rats. The results of fertility studies revealed that there was an increase in the mating index in experimental rats with an increase in the pre- and post-implantation losses in rats cohabited with treated animals indicating poor male reproductive performance.     

Carcinoembryonic antigen, alpha-fetoprotein, and prostate-specific antigen in the sera of industrial workers exposed to phenol, formaldehyde, urea, and mixed vapors

Exposure to certain industrial agents has been thought to have carcinogenic potential, both for employees who work closely with agents and for the general population that comes into contact with them. The objective of the present study is to evaluate the changes at the cellular level or at the level of cellular metabolism products present in the biological fluid, and to detect early stages of the carcinogenic process resulting from the exposure of industrial environmental hazards. Carcinoembryonic antigen (CEA), alpha-fetoproteins (AFP), and prostate-specific antigen (PSA) were measured in sera of workers (n = 51), who were divided into 4 groups: group I, workers exposed to phenol; group II, workers exposed to formaldehyde; group III, workers exposed to urea; and group IV, workers exposed to mixed vapor, plus a reference control healthy group (n = 15). The results showed that 75% of the workers exposed to phenol, 75% of the workers exposed to urea, 83.3% of workers exposed to formalin, and 92.3% of the workers exposed to mixed vapors had raised values of serum CEA (S-CEA) above normal value of the control group. Also, 23% of workers exposed to mixed vapors, 44% of workers exposed to formalin, 50% of workers exposed to phenol, and 62.5% of workers exposed to urea had raised values of serum AFP (S-AFP) above normal value of control group. Finally, 16.6% of workers exposed to phenol, 23% of workers exposed to mixed vapors, and 33.3% of workers exposed to formalin had raised values of serum PSA (S-PSA) above the normal value of control group; there were no raised values of S-PSA in workers exposed to urea. No significant difference was found in the activities of AST and ALT in group I, but a highly significant increase was found in the AST activities for groups II and IV and the ALT activities for groups III and IV. A significant difference was found in the activity of ALT in group II and in AST for group III. There was no significant difference in the levels of albumin in groups I, II, and III, whereas albumin levels were significantly decreased in group IV. No significant change was found in the level of urea and creatinine in all groups except for group III, where serum levels of creatinine were significantly decreased. From our findings, we concluded that S-CEA can be used as an important prognostic screening marker for early prediction for malignancy, and for management of workers with lung cancer who are exposed to the environmental hazards in industrial factories. Furthermore, S-AFP can be used also as a biomarker if it is carried out and correlated with S-CEA.     

三硝基甲苯对雄性生殖毒性的研究

急性、亚急性和亚慢性TNT染毒大鼠睾丸铜锌含量和多种酶活性皆有所变化;睾丸和血清睾酮含量下降。大鼠辜丸游离间质细胞与TNT共同孵育时,睾酮形成量明显下降;间质细胞与TNT孵育后,活性氧与脂质过氧化阳性物质含量明显增加。补锌在一定程度上能拮抗TNT对大鼠的生殖毒性。横断面调查表明,TNT接触男工自觉性功能降低者增加,血清睾酮含量下降,精液常规检查有阳性所见。     

Carcinoembryonic Antigen,Alpha-fetoprotein,and Prostate-Specific Antigen in the Sera of Industrial Workers Exposed to Phenol,Formaldehyde, Urea,and Mixed Vapors

Exposure to certain industrial agents has been thought to have carcinogenic potential, both for employees who work closely with agents and for the general population that comes into contact with them. The objective of the present study is to evaluate the changes at the cellular level or at the level of cellular metabolism products present in the biological fluid, and to detect early stages of the carcinogenic process resulting from the exposure of industrial environmental hazards. Carcinoembryonic antigen (CEA), alpha-fetoproteins (AFP), and prostate-specific antigen (PSA) were measured in sera of workers (n = 51), who were divided into 4 groups: group I, workers exposed to phenol; group II, workers exposed to formaldehyde; group III, workers exposed to urea; and group IV, workers exposed to mixed vapor, plus a reference control healthy group (n = 15). The results showed that 75% of the workers exposed to phenol, 75% of the workers exposed to urea, 83.3% of workers exposed to formalin, and 92.3% of the workers exposed to mixed vapors had raised values of serum CEA (S-CEA) above normal value of the control group. Also, 23% of workers exposed to mixed vapors, 44% of workers exposed to formalin, 50% of workers exposed to phenol, and 62.5% of workers exposed to urea had raised values of serum AFP (S-AFP) above normal value of control group. Finally, 16.6% of workers exposed to phenol, 23% of workers exposed to mixed vapors, and 33.3% of workers exposed to formalin had raised values of serum PSA (S-PSA) above the normal value of control group; there were no raised values of S-PSA in workers exposed to urea. No significant difference was found in the activities of AST and ALT in group I, but a highly significant increase was found in the AST activities for groups II and IV and the ALT activities for groups III and IV. A significant difference was found in the activity of ALT in group II and in AST for group III. There was no significant difference in the levels of albumin in groups I, II, and III, whereas albumin levels were significantly decreased in group IV. No significant change was found in the level of urea and creatinine in all groups except for group III, where serum levels of creatinine were significantly decreased. From our findings, we concluded that S-CEA can be used as an important prognostic screening marker for early prediction for malignancy, and for management of workers with lung cancer who are exposed to the environmental hazards in industrial factories. Furthermore, S-AFP can be used also as a biomarker if it is carried out and correlated with S-CEA.     

Clinical and biochemical changes in chronically exposed organophosphate workers

Health effects of occupational organophosphate exposure were investigated by subjecting 22 workers chronically exposed to an organophosphate pesticide, fenthion (O,O-dimethyl-O-(4-methylmercapto-3-methylphenyl)-phosphorothioate) to clinical evaluation, estimation of serum cholinesterase, serum alkaline phosphatase (SAP), serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT). The mean age of the workers was 31 years and the mean duration of fenthion exposure 8.2 years. Headache (59%), giddiness (50%), ocular symptoms (27%) and paresthesia (18%) were the commonest symptoms. Serum acetylcholinesterase and butyrylcholinesterase levels were significantly lower than in controls. After withdrawing the workers from organophosphate exposure for 3 weeks, the follow-up study revealed absence of transient symptoms. There was no change in their neurological status, and serum acetylcholinesterase and butyrylcholinesterase levels were raised significantly, whereas the other serum enzymes showed no significant change. For monitoring of occupational organophosphate exposure, the importance of both clinical and biochemical parameters is emphasised.     

Determination of chromosome aberrations in workers in a petroleum refining factory

Human exposure to benzene is derived occupationally from the petrochemical and petroleum refining industries. This study was performed to determine whether the frequencies of chromosome aberrations in workers exposed to low levels of benzene in a petroleum refining factory were elevated compared to an unexposed control group. The study population was comprised of 178 exposed workers and 36 unexposed workers. The frequencies of chromatid deletions and total chromosome aberrations in workers exposed to benzene were significantly higher compared to the unexposed control group. The frequency of total chromosome aberration was 4.20 per 500 metaphase cells in the exposed workers, whereas the frequency was 2.24 per 500 metaphase cells in the unexposed control group. The frequencies of total chromosome aberrations were significantly associated with benzene concentration after adjusting for confounding variables such as age, smoking status, and alcohol intake. The frequencies of chromosome aberrations were significantly increased in workers with low white blood cell counts (below 4000 cells/mm3) compared to those with high white blood cell counts (above 4000 cells/mm3). A reduced white blood cell count (below 4000/mm3) is suggestive of chronic exposure to benzene. In conclusion chronic benzene exposure and preclinical signs, such as reduced white blood cell counts, may be monitored by chromosome aberrations analysis.     

Biomarkers of oxidative stress and DNA damage in agricultural workers: a pilot study

Oxidative stress and DNA damage have been proposed as mechanisms linking pesticide exposure to health effects such as cancer and neurological diseases. A study of pesticide applicators and farmworkers was conducted to examine the relationship between organophosphate pesticide exposure and biomarkers of oxidative stress and DNA damage. Urine samples were analyzed for OP metabolites and 8-hydroxy-2'-deoxyguanosine (8-OH-dG). Lymphocytes were analyzed for oxidative DNA repair activity and DNA damage (Comet assay), and serum was analyzed for lipid peroxides (i.e., malondialdehyde, MDA). Cellular damage in agricultural workers was validated using lymphocyte cell cultures. Urinary OP metabolites were significantly higher in farmworkers and applicators (p<0.001) when compared to controls. 8-OH-dG levels were 8.5 times and 2.3 times higher in farmworkers or applicators (respectively) than in controls. Serum MDA levels were 4.9 times and 24 times higher in farmworkers or applicators (respectively) than in controls. DNA damage (Comet assay) and oxidative DNA repair were significantly greater in lymphocytes from applicators and farmworkers when compared with controls. Markers of oxidative stress (i.e., increased reactive oxygen species and reduced glutathione levels) and DNA damage were also observed in lymphocyte cell cultures treated with an OP. The findings from these in vivo and in vitro studies indicate that organophosphate pesticides induce oxidative stress and DNA damage in agricultural workers. These biomarkers may be useful for increasing our understanding of the link between pesticides and a number of health effects.     

Chronic exposure of Rana pipiens tadpoles to UVB radiation and the estrogenic chemical 4-tert-octylphenol

While adverse effects of exposure to ultraviolet B radiation (UVBR) and environmental pollutants on amphibians have been documented, few studies examined the effects of interactions between environmental stressors on amphibian health. Here the impacts of chronic exposure to UVBR and the estrogenic chemical 4-tert-octylphenol (OP), alone and in combination, on the survival, development, growth, and metamorphosis of Rana pipiens (northern leopard frog) tadpoles are evaluated. Tadpoles were exposed to environmentally relevant levels of OP (0.01 or 10 nM), with and without exposure to UVBR (approximately 0.22 W/m2). After 8 mo of exposure, animals were transferred to a clean-water grow-out system for 3 additional mo. There was no effect of treatments on the weights of animals at wk 42 or on the age, snout-vent length (SVL), and weights of tadpoles at forelimb emergence (FLE). However, tadpoles exposed to UVBR had markedly delayed development and significantly fewer reached metamorphosis compared to control animals. Although exposure to UVBR and OP together produced the highest incidence of mortality and developmental anomalies, UVBR alone was sufficient to produce significant mortality of tadpoles, and exposure to UVBR or OP alone induced a significant increase in malformations and abnormalities. The malformations observed consisted mainly of spinal curvature. Our results show that chronic exposure to environmental levels of UVBR or OP alone exerts lethal and/or sublethal effects on R. pipiens tadpoles.     

Alterations of serum hormone levels in male workers occupationally exposed to cadmium

In order to investigate the influence of occupational exposure to cadmium (Cd) on the levels of serum hormone, a cross-sectional study was undertaken in male workers. Creatinine-adjusted urinary cadmium (UCd) was used as the indicator of cadmium body burden in workers. The levels of serum testosterone (T), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were determined by radioimmunoassay and enzyme immunoassay, respectively. The results showed that with cadmium exposure, the levels of serum testosterone and LH were significantly increased after controlling for confounding factors such as age, smoking habits, and alcohol consumption. However, no significant cadmium-associated changes in the levels of serum FSH were found. At the same time, a significant negative correlation of serum testosterone levels with age was detected. In contrast, the levels of serum FSH and LH were significantly elevated with increasing age. When taking the marital status into consideration, only significantly elevated FSH levels were noted in married workers after controlling for confounding factors. These results indicate that occupational cadmium exposure and other factors such as age and marital status may independently contribute to alterations in the levels of serum sex hormones in males.     

Serum neopterin in workers exposed to inorganic dust containing free crystalline silicon dioxide

The study was conducted among 92 male workers, divided into two groups depending on workplace and level of inorganic dust containing free crystalline SiO₂ in the work environment, and 43 healthy workers without exposure to dust aerosols. The measured inhalable and respirable dust concentrations, as well as the concentration of free crystalline silica (FCS) in the respirable fraction were different for the two groups, but the percentage of free crystalline silica in the respirable fraction was almost identical. Significantly higher neopterin levels were found in workers exposed to dust, compared to the control group: 12.72 nmol/L and 6.32 nmol/L respectively (p<0.05). No significant difference was found between serum neopterin levels in both groups of the exposed workers. Among the groups with different length of service, a statistically higher neopterin level was evident only in the workers with length of service less than 10 years (p<0.05). The correlation analysis did not find a significant dependence of neopterin levels on the age of the studied workers or on the duration of smoking in packet years. The difference between neopterin levels in smokers and non-smokers was nonsignificant. The results obtained show that increased neopterin levels in the exposed workers are not influenced by individual features, duration and level of exposure to inorganic dust, but mostly by the presence of FCS in the respirable fraction.