Reproductive male-mediated risk: spontaneous abortion among wives of pesticide applicators

Occupational Exposure to Physical and Chemical Risk Factors: A Systematic Review of Reproductive Pathophysiological Effects in Women and Men

The human reproductive system can be affected by occupational exposure to many physical and chemical risk factors. This study was carried out to review the studies conducted on the issue of the pathophysiological effects of occupational physical and chemical risk factors on the reproductive system of females and males. In this systematic review, the databases such as "Google Scholar," "Pub-Med," "Scopus," and "Web of Science" were used. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA 2020), the studies included in our study were published between 2000 and 2021. In order to extract the required data, all sections of the articles were reviewed. Out of 57 articles we reviewed, 34 articles were related to field studies and 23 articles to clinical studies. Among them, 43 studies dealt with the pathophysiological effects of chemical agents, six studies dealt with the pathophysiological effects of physical factors, and 8 studies dealt with the pathophysiological effects of physicochemical factors on the human reproductive system. Physical (noise, heat, and radiofrequency radiation) and chemical (such as carbamate and organophosphate pesticides, benzene, toluene, xylene, formaldehyde, NO₂, CS₂, manganese, lead, nickel, and n-hexane) risk factors had pathophysiological effects on the human reproductive system. The presence of these risk factors in the workplace caused damage to the human reproductive system. The rate of these negative pathophysiological effects can be reduced by performing appropriate managerial, technical, and engineering measures in work environments.

Pesticide exposure among Bolivian farmers: associations between worker protection and exposure biomarkers

The use of pesticides has increased during the past decades, also increasing the risk of exposure to toxic pesticides that can cause detrimental health effects in the future. This is of special concern among farmers in low-to-middle-income countries that may lack proper training in the safe use of these chemicals. To assess the situation in Bolivia a cross-sectional study in three agricultural communities was performed (n = 297). Handling, use of personal protective equipment (PPE) and pesticide exposure were assessed by a questionnaire and measurements of urinary pesticide metabolites (UPMs). Results showed that methamidophos (65%) and paraquat (52%) were the most commonly used pesticides and that 75% of the farmers combined several pesticides while spraying. Notably, only 17% of the farmers used recommended PPEs while 84% reported to have experienced symptoms of acute pesticide poisoning after spraying. UPM measurements indicated high levels of exposure to chlorpyrifos, pyrethroids and 2,4D and that men generally were more highly exposed compared to women. Our study demonstrates that farmers who are better at following recommendations for pesticide handling and use of PPE had a significantly lower risk of having high UPM levels of most measured pesticides. Our results thus confirm the need of proper training of farmers in low-to-middle-income countries in proper protection and pesticide handling in order to reduce exposure levels and health problems.

Environmental & occupational exposure & female reproductive dysfunction

All individuals are exposed to certain chemical, physical, biological, environmental as well as occupational factors. The data pertaining to role of these factors on female reproduction are scanty as compared to male. The available data suggest the adverse effects of certain toxicants, viz., metals such as lead, cadmium and mercury, pesticides such as bis(4-chlorophenyl)-1,1,1-trichloroethane and organic solvent such as benzene, toluene and ionizing radiation on the female reproductive system affecting directly the organ system or impacting in directly through hormonal impairments, molecular alterations, oxidative stress and DNA methylation impairing fertility as well as pregnancy and its outcomes. Thus, there is a need for awareness and prevention programme about the adverse effects of these factors and deterioration of female reproductive health, pregnancy outcome and offspring development as some of these chemicals might affect the developing foetus at very low doses by endocrine disruptive mechanism.

Health Effects of Pesticides on Pregnant Women and Children

Pesticides, along with hybrid seeds and fertilizers, are an integral part of the green revolution and are used to control and eradicate disease vectors for the improvement of agricultural production. Pesticides is an umbrella term for insecticides, nematocides, fungicides, herbicides, fumigants, repellents, and attractants. Pesticides are used against unwanted plants and animals to control diseases and losses. Efforts at different levels may help to reduce the impact of pesticides on newborn babies and on pregnant women. Different efforts can be considered at clinical, educational, and policymaking institutes. Use of risk assessment tools, encouragement of organic diets, educating parents working in agricultural fields from hazards of pesticides particularly in pregnancy and breast feeding, implementation of integrated pest management (IPM) programs, and encouraging policies supporting IPM can help in tackling the menace of pesticide hazards.

Climate variability, perceptions and political ecology: Factors influencing changes in pesticide use over 30 years by Zimbabwean smallholder cotton producers

Pesticides represent a potential public health hazard of note in farming communities. Accumulating evidence indicates that some pesticides used in agriculture act as hormone disrupters, with the potential to result in chronic health effects. Despite such a growing evidence base, pesticides remain the preferred method of pest control in agriculture worldwide. In many parts of Sub-Saharan Africa, usage is on the increase. This qualitative study assessed changes in the usage of pesticides by Zimbabwean smallholder cotton farmers in the past 30 years. Farmers reported an increase in the usage of pesticides, specifically insecticides, since the early 1980s. An increase in pest populations was also reported. The findings suggested a bi-directional causal relationship between the increase in pest population and the increase in pesticide use. Factors which emerged to have collectively impacted on the changes include climate variability, limited agency on the part of farmers, power dynamics involving the government and private cotton companies and farmers' perceptions and practices. An Integrated Pest Management Policy for Zimbabwe is recommended to facilitate integration of chemical controls with a broad range of other pest control tactics. Continuous farmer education and awareness raising is further recommended, since farmers' perceptions can influence their practices.

Absence of t(14;18) chromosome translocation in agricultural workers after short-term exposure to pesticides

Exposure to pesticides represents a potential health risk for the general population and for agricultural workers in particular. Some researchers observed that occupational exposure to pesticides is associated with risk of non‑Hodgkin's lymphoma (NHL). The chromosomal translocation t(14;18)(q32;q21) is one of the most common chromosomal abnormalities in NHL. The aim of this study was to detect the effects of pesticides on t(14;18) chromosome translocation in agricultural workers after short-term exposure. Fifty-two workers occupationally exposed to pesticides (fungicides and insecticides) and 52 non-exposed were recruited. The farm workers were on average exposed to pesticides for ~3.7 h a day for 5 years. The frequency of BCL2-IGH t(14;18) translocation in workers occupationally exposed to pesticides was 10% (5 of 52) vs. 8% (4 of 52) in the control group. Overall, these data suggest that no significant association between occupational exposure to pesticides and an increased frequency of the chromosomal translocation BCL2-IGH t(14;18) in farmers was observed. However, further studies with a higher number of subjects exposed to pesticides are necessary to confirm this observation.

Congenital malformations according to etiology in newborns from the floricultural zone of Mexico state

Birth defects are the number one cause of child mortality worldwide and in 2010 it was the second cause in Mexico. Congenital malformations are a public health issue, because they cause infant mortality, chronic disease and disability. The origin can be genetic, environmental or unknown causes. Among environmental contaminants, pesticides stand out. In this study, we determine the frequency and etiology of congenital malformations in newborns (NBs) of a floricultural community and we compare it with that in the urban community. For 18 months, the NBs were monitored at the Tenancingo General Hospital and the Mother and Child Gynecology and Obstetrics Hospital (IMIEM) in Toluca. The identification of these malformations was carried out in accordance with the WHO. In Tenancingo, 1149 NBs were viewed, where 20% had some kind of congenital malformations. While in the IMIEM, 5069 were reviewed and 6% had some malformation. According to the etiology, in Tenancingo, 69% were multifactorial, 28% were monogenetic and 2% were chromosomal. In the IMIEM, 47% were multifactorial, then 18.3% were monogenetic and 2.8% were chromosomal. There was a significant difference between the global frequency of malformations and the multifactorial etiology of both institutions. Our results show that congenital malformations in the NBs occurred more frequently in the floricultural zone and that because the percentage of multifactorial etiology is higher, it is likely there is an association with exposure to pesticides.

Aerial pesticide application causes DNA damage in pilots from Sinaloa, Mexico

The use of pesticides in agricultural production originates residues in the environment where they are applied. Pesticide aerial application is a frequent source of exposure to pesticides by persons dedicated to agricultural practices and those living in neighboring communities of sprayed fields. The aim of the study was to assess the genotoxic effects of pesticides in workers occupationally exposed to these chemicals during their aerial application to agricultural fields of Sinaloa, Mexico. The study involved 30 pilots of airplanes used to apply pesticides via aerial application and 30 unexposed controls. Damage was evaluated through the micronucleus assay and by other nuclear abnormalities in epithelial cells of oral mucosa. The highest frequency ratios (FR) equal to 269.5 corresponded to binucleated cells followed by 54.2, corresponding to cells with pyknotic nuclei, 45.2 of cells with chromatin condensation, 3.7 of cells with broken-egg, 3.6 of cells with micronucleus, and 2.0 of karyolytic cells. Age, worked time, smoking, and alcohol consumption did not have significant influence on nuclear abnormalities in the pilots studied. Pesticide exposure was the main factor for nuclear abnormality results and DNA damage. Marked genotoxic damage was developed even in younger pilots with 2 years of short working period, caused by their daily occupational exposure to pesticides.

Biomonitoring of agricultural workers exposed to pesticide mixtures in Guerrero state, Mexico, with comet assay and micronucleus test

The aim of this study was to evaluate the genotoxic effect of pesticides in exfoliated buccal cells of workers occupationally exposed in Guerrero, Mexico, using the comet assay and the micronucleus test. The study compared 111 agricultural workers in three rural communities (Arcelia 62, Ajuchitlan 13, and Tlapehuala 36), with 60 non-exposed individuals. All the participants were males. The presence of DNA damage was investigated in the exfoliated buccal cells of study participants with the comet assay and the micronucleus (MN) test; comet tail length was evaluated in 100 nuclei and 3000 epithelial cells of each individual, respectively; other nuclear anomalies such as nuclear buds, karyolysis, karyorrhexis, and binucleate cells were also evaluated. Study results revealed that the tail migration of DNA and the frequency of MN increased significantly in the exposed group, which also showed nuclear anomalies associated with cytotoxic or genotoxic effect. No positive correlation was noted between exposure time and tail length and micronuclei frequencies. No significant effect on genetic damage was observed as a result of age, smoking, and alcohol consumption. The MN and comet assay in exfoliated buccal cells are useful and minimally invasive methods for monitoring genetic damage in individuals exposed to pesticides. This study provided valuable data for establishing the possible risk to human health associated with pesticide exposure.

Estrogenic endocrine-disrupting chemicals: molecular mechanisms of actions on putative human diseases

Endocrine-disrupting chemicals (EDC), including phthalates, bisphenol A (BPA), phytoestrogens such as genistein and daidzein, dichlorodiphenyltrichloroethane (DDT), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), are associated with a variety of adverse health effects in organisms or progeny by altering the endocrine system. Environmental estrogens, including BPA, phthalates, and phytoestrogens, are the most extensively studied and are considered to mimic the actions of endogenous estrogen, 17β-estradiol (E2). Diverse modes of action of estrogen and estrogen receptors (ERα and ERβ) have been described, but the mode of action of estrogenic EDC is postulated to be more complex and needs to be more clearly elucidated. This review examines the adverse effects of estrogenic EDC on male or female reproductive systems and molecular mechanisms underlying EDC effects that modulate ER-mediated signaling. Mechanisms of action for estrogenic EDC may involve both ER-dependent and ER-independent pathways. Recent findings from systems toxicology of examining estrogenic EDC are also discussed.

Effect of chronic pesticide exposure in farm workers of a Mexico community

Pesticides are frequently used substances worldwide, even when the use of some of them is forbidden due to the recognized adverse effect they have on the health of not only the people who apply the pesticides, but also of those that consume the contaminated products. The objectives of this study were to know the health issues of farm workers chronically exposed to pesticides, to evaluate possible damage at genetic level, as well as to explore some hepatic, renal, and hematological alterations. A transversal comparative study was performed between 2 groups, one composed of 25 farm workers engaged in pesticide spraying, and a control group of 21 workers not exposed to pesticides; both groups belonged to the Nextipac community in Jalisco, Mexico. Each member of both groups underwent a full medical history. Blood samples were taken from all farm workers in order to obtain a complete blood count and chemistry, clinical chemistry, lipid profile, liver and kidney function tests, erythrocyte cholinesterase quantification, lipid peroxidation profile, and free DNA fragment quantification. For the information analysis, central tendency and dispersion measurements were registered. In order to know the differences between groups, a cluster multivariate method was used, as well as prevalence reasons. The most used pesticides were mainly organophosphates, triazines and organochlorine compounds. The exposed group showed acute poisoning (20% of the cases) and diverse alterations of the digestive, neurological, respiratory, circulatory, dermatological, renal, and reproductive system probably associated to pesticide exposure. More importantly, they presented free DNA fragments in plasma (90.8 vs 49.05 ng/mL) as well as a higher level of lipid peroxidation (41.85 vs. 31.91 nmol/mL) in comparison with those data from unexposed farm workers. These results suggest that there exist health hazards for those farm workers exposed to pesticides, at organic and cellular levels.

DNA damage in workers occupationally exposed to pesticide mixtures

Pesticides are used in agriculture to protect crops but represent at the same time a potential risk to farmers and environment. The aim of this work is the evaluation of 54 subjects occupationally exposed to pesticides and 30 subjects as a control group using the quantification of DNA damage level by means of the alkaline Comet assay and the evaluation of repair processes. Damage index Comet assay (DICA) and damage index repair assay (DIRA) were studied in 27 pesticide applicator workers, 27 non-pesticide applicators and controls. Our results show that both exposed groups revealed significant increase in DICA when compared with controls (P < 0.0001), as well as in DIRA (P < 0.0001). However, the spraying group exhibited a marginally significant difference in DICA (P = 0.05) when years of exposure are considered and a significant difference (P < 0.05) when the personal protective equipment used by individuals was taken as a comparison factor. The influence of confounding factors on the genotoxic effects of occupational exposure to pesticides was investigated and no significant differences were observed considering age, gender, smoking and alcohol consumption in relation to DICA and DIRA. Since DNA damage is an important step in events leading from carcinogen exposure to cancer disease, our study highlights the potential health risk associated with agrochemical exposure in developing countries with vast cultivated areas, such as Argentina.

DNA damage in Pakistani agricultural workers exposed to mixture of pesticides

A cross-sectional study was designed to determine whether occupational exposure to a complex mixture of pesticides results in a significant increase of DNA damage in farmers chronically exposed to pesticides in open fields. Leukocytes from 47 agriculture workers exposed to pesticides and 50 controls were evaluated with comet assay. Workers recruitment was based on their exposure to pesticides during the spraying season on cotton crop. Serum from these individuals was also analyzed for pesticides presence using high performance liquid chromatography. Statistically significant difference (P < 0.001) in DNA damage of exposed individuals (mean +/- S.D 14.80 +/- 3.04 microm) was observed when compared with control group (6.54 +/- 1.73 microm) as studied on the basis of comet tail length. Smokers had significantly higher mean comet tail length than nonsmokers and ex-smokers in both workers (20.26 +/- 3.53 vs. 14.19 +/- 4.25, P < 0.001) and controls (7.86 +/- 1.09 vs. 5.80 +/- 1.59, P < 0.001), whereas age had a minimal effect on DNA damage (P < 0.05). The length of pesticide exposure is positively associated with DNA damage in exposed individuals (P < 0.001). Our study shows that chronic exposure to pesticides produces DNA damage in pesticide sprayers and suggests that this type of monitoring is recommended in preventive policies for pesticide sprayers.

Keokuk County rural health study: self-reported use of agricultural chemicals and protective equipment

The Keokuk County Rural Health Study is a population-based study of an agricultural community in Iowa. The study includes in-depth evaluations of respiratory disease, injury, and other health outcomes in relation to environmental and occupational exposures. This article reports descriptive findings on pesticide use from among the 1191 participants completing occupational surveys. Fifty-one percent (612) of respondents (farmers and non-farmers) had applied insecticides including lawn and garden chemicals at home during the past year. Thirty-three percent (395) of respondents had personally mixed or applied farm chemicals during their life. One-hundred and four had a current pesticide applicator's license. Information on the specific types of pesticides and protective measures used was obtained for the 144 individuals who had mixed or applied pesticides on farms within the previous year. Of these individuals, 67% worked with fertilizers, 49% used herbicides, 48% used crop insecticides, 28% used crop storage insecticides, 45% applied livestock insecticides, and 9% worked with fungicides. The use of personal protective equipment such as gloves, aprons, and respirators varied depending on the chemical. A substantial proportion did not use gloves even for mixing. Thirty-five percent reported at least one suspected work-related symptom after working with pesticides during the previous year. The lack of differences in protective equipment use between applicators who have completed pesticide applicator training courses and those who have not suggests a need to develop more effective training methods. The increased use of protective equipment when applying odorous agrochemicals suggests that addition of an odorant to more toxic pesticides may be a successful intervention strategy.

Epidemiologic evidence of relationships between reproductive and child health outcomes and environmental chemical contaminants

This review summarizes the level of epidemiologic evidence for relationships between prenatal and/or early life exposure to environmental chemical contaminants and fetal, child, and adult health. Discussion focuses on fetal loss, intrauterine growth restriction, preterm birth, birth defects, respiratory and other childhood diseases, neuropsychological deficits, premature or delayed sexual maturation, and certain adult cancers linked to fetal or childhood exposures. Environmental exposures considered here include chemical toxicants in air, water, soil/house dust and foods (including human breast milk), and consumer products. Reports reviewed here included original epidemiologic studies (with at least basic descriptions of methods and results), literature reviews, expert group reports, meta-analyses, and pooled analyses. Levels of evidence for causal relationships were categorized as sufficient, limited, or inadequate according to predefined criteria. There was sufficient epidemiological evidence for causal relationships between several adverse pregnancy or child health outcomes and prenatal or childhood exposure to environmental chemical contaminants. These included prenatal high-level methylmercury (CH(3)Hg) exposure (delayed developmental milestones and cognitive, motor, auditory, and visual deficits), high-level prenatal exposure to polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs), and related toxicants (neonatal tooth abnormalities, cognitive and motor deficits), maternal active smoking (delayed conception, preterm birth, fetal growth deficit [FGD] and sudden infant death syndrome [SIDS]) and prenatal environmental tobacco smoke (ETS) exposure (preterm birth), low-level childhood lead exposure (cognitive deficits and renal tubular damage), high-level childhood CH(3)Hg exposure (visual deficits), high-level childhood exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (chloracne), childhood ETS exposure (SIDS, new-onset asthma, increased asthma severity, lung and middle ear infections, and adult breast and lung cancer), childhood exposure to biomass smoke (lung infections), and childhood exposure to outdoor air pollutants (increased asthma severity). Evidence for some proven relationships came from investigation of relatively small numbers of children with high-dose prenatal or early childhood exposures, e.g., CH(3)Hg poisoning episodes in Japan and Iraq. In contrast, consensus on a causal relationship between incident asthma and ETS exposure came only recently after many studies and prolonged debate. There were many relationships supported by limited epidemiologic evidence, ranging from several studies with fairly consistent findings and evidence of dose-response relationships to those where 20 or more studies provided inconsistent or otherwise less than convincing evidence of an association. The latter included childhood cancer and parental or childhood exposures to pesticides. In most cases, relationships supported by inadequate epidemiologic evidence reflect scarcity of evidence as opposed to strong evidence of no effect. This summary points to three main needs: (1) Where relationships between child health and environmental exposures are supported by sufficient evidence of causal relationships, there is a need for (a) policies and programs to minimize population exposures and (b) population-based biomonitoring to track exposure levels, i.e., through ongoing or periodic surveys with measurements of contaminant levels in blood, urine and other samples. (2) For relationships supported by limited evidence, there is a need for targeted research and policy options ranging from ongoing evaluation of evidence to proactive actions. (3) There is a great need for population-based, multidisciplinary and collaborative research on the many relationships supported by inadequate evidence, as these represent major knowledge gaps. Expert groups faced with evaluating epidemiologic evidence of potential causal relationships repeatedly encounter problems in summarizing the available data. A major driver for undertaking such summaries is the need to compensate for the limited sample sizes of individual epidemiologic studies. Sample size limitations are major obstacles to exploration of prenatal, paternal, and childhood exposures during specific time windows, exposure intensity, exposure-exposure or exposure-gene interactions, and relatively rare health outcomes such as childhood cancer. Such research needs call for investments in research infrastructure, including human resources and methods development (standardized protocols, biomarker research, validated exposure metrics, reference analytic laboratories). These are needed to generate research findings that can be compared and subjected to pooled analyses aimed at knowledge synthesis.

The influence of the environment and other exogenous agents on spontaneous abortion risk

It is estimated that close to 30% of all pregnancies end in spontaneous abortion. Although about 60% of spontaneous abortions are thought to be due to genetic, infectious, hormonal, and immunological factors, the role of the environment remains poorly understood. Pregnancy involves a delicate balance of hormonal and immunological functions, which may be affected by environmental substances. Many toxic substances that are persistent in the environment and accumulate in the fatty tissues may disrupt this equilibrium. This overview addresses known risk factors for spontaneous abortions and examines the role, if any, that environmental factors (chemical and physical) may play in the etiology of this adverse health outcome.

The environmental health of children: priorities in Europe

OBJECTIVES

To evaluate existing research on the environmental health of children and provide a prioritised list of risk factors and policy recommendations for action, the Policy Interpretation Network on Children's Health and Environment (PINCHE) was set up within EU FP5 (QLK4-2002-02395). The project focused on air pollutants, carcinogens, neurotoxicants and noise. PINCHE was a multidisciplinary and multinational network of representatives from science, industry, NGOs, and consumer and patient organisations in Europe.

MATERIALS AND METHODS

A literature search was performed using the Pubmed, Embase and Toxline databases. The quality of the gathered articles was assessed and their information and relevance was interpreted within a systematic framework. Information related to exposure, epidemiology, and toxicology was analysed separately and then a risk evaluation of particular environmental factors was made. Socioeconomic factors were specifically taken into account. The results were compiled, and considering the present regulatory situation, policy recommendations for action were made. Finally, the risk factors and policy recommendations were prioritised through a process of discussion between all the partners.

RESULTS AND CONCLUSIONS

PINCHE concluded that outdoor air pollutants (especially traffic-related), environmental tobacco smoke, allergens, and mercury were high priorities with an urgent need for action. Brominated flame retardants, lead, PCBs and dioxins, ionising and solar radiation, and some noise sources were classified as being of medium priority. Some toxins were given low priority, based on few exposed children, relatively mild health effects or an improving situation due to past policy measures. We recognise the shortcomings of such a prioritisation and, though some measures are more urgent than others, emphasise that ideally all policy measures should be carried out without delay for all toxins. This priority list must be continuously revised, the precautionary principle should be central to all decisions, and the focus should be on safe exposure levels for children.

Paternal age and spontaneous abortion

OBJECTIVE

To evaluate the influence of paternal age upon spontaneous abortion.

METHODS

This case-control study of 13,865 women draws on data from women's antenatal or postpartum interviews in the Jerusalem Perinatal Study, a population-based cohort derived from 92,408 births in 1964-1976. Case women (n=1,506) reported spontaneous abortion in the pregnancy preceding the interview; they were compared with women reporting live births in their previous pregnancy (n=12,359). Logistic regression was used to adjust for maternal age, maternal diabetes, maternal smoking, history of spontaneous abortions before the index pregnancy, parity at interview, and interval between the index pregnancy and the interview.

RESULTS

The adjusted odds ratio for spontaneous abortion was 0.59 (95% confidence interval 0.45-0.76, P< .0001) for pregnancies conceived from fathers aged younger than 25 years compared with those from fathers aged 25-29 years. For fathers age 40 years or older the odds ratio for spontaneous abortion was 1.6 (95% confidence interval 1.2-2.0, P=.0003) when compared with the same reference group.

CONCLUSION

Increasing paternal age is significantly associated with spontaneous abortion, independent of maternal age and multiple other factors.

Maternal and paternal occupational exposure to agricultural work and the risk of anencephaly

AIMS

To evaluate the association between parental occupational exposure to agricultural work and the risk of anencephaly in three Mexican states.

METHODS

A paired case control study (1:1) was done based on records of the Epidemiological Surveillance System of Neural Tube Defects in Mexico; 151 cases of anencephaly of more than 20 weeks' gestation were selected between March 2000 and February 2001. Controls were selected from the same maternity services as those of the cases and were born alive without congenital malformations. Information was obtained from both parents by means of a general questionnaire, a food frequency questionnaire, and a specific questionnaire on occupational exposure to pesticides. Exposures were analysed with emphasis on the three months before and one month after the last menstruation periods (acute risk period (ARP)), as well as exposure prior to the above mentioned period (non-acute risk period (NARP)).

RESULTS

The children of mothers who worked in agriculture in the ARP had a greater risk of anencephaly (OR = 4.57, 95% CI 1.05 to 19.96). The risk of fathers having a child with anencephaly was greater in those who applied pesticides irrespective of whether it was done in the ARP or the NARP (OR = 2.50, 95% CI 0.73 to 8.64; and OR = 2.03, 95% CI 0.58 to 7.08, respectively).

CONCLUSIONS

These results support the hypothesis of the effect of maternal exposure to agricultural work on anencephaly and suggest that exposure of the father to pesticides in the periconceptional period or prior to this can also increase the risk of having an anencephalic child.

Maternal miscarriage history and risk of anencephaly

Women with a history of reproductive loss may be at an increased risk of having an unfavourable outcome in subsequent pregnancies. Using data from a matched case-control study based on the record of the Epidemiological Surveillance System of Neural Tube Defects, we evaluated the association between history of maternal reproductive loss and the risk of anencephaly in three Mexican states. Mothers of 157 cases of anencephaly and 151 controls born during the period March 2000 to February 2001, were interviewed about their reproductive history and other additional factors, including socio-economic characteristics, prenatal care, use of tobacco and alcohol, presence of chronic diseases, acute illnesses and fever during the periconceptional period, and consumption of multivitamins and medicines during this period; mothers who reported no prior pregnancies were excluded from the analysis; 58 matched case-control pairs were used for the analysis. After adjusting for potential confounders, women with a history of miscarriage in previous pregnancies had 4.58 times more risk of having a child with anencephaly, than those who did not have this history; OR = 4.58, [95% CI 1.22, 17.23]. Our results suggest that a history of previous miscarriages is a risk indicator for anencephaly in future gestations. This does not necessarily mean that the miscarriage itself is the cause, but that common mechanisms could be involved in the aetiology of both events. Thus, women who have had histories of reproductive losses, especially miscarriages, should be a priority group for the primary and secondary prevention of neural tube defects.

Cytogenetic analysis of Pakistani individuals occupationally exposed to pesticides in a pesticide production industry

Although several cytogenetic biomonitoring studies on workers exposed to pesticides have been reported, there is only limited information on this topic from developing countries where pesticides have been widely used over the years. People in developing countries are at higher risk from exposure, due to poor working conditions and a lack of awareness of the potential hazards during manufacturing and application of the pesticides. The present study has assessed the genotoxic effects of pesticides on workers involved in the pesticide manufacturing industry. Subjects in the exposed group (29) were drawn from workers at a pesticide production plant in district Multan (Pakistan). The control group (unexposed) composed of 35 individuals from the same area but was not involved in pesticide production. Liver enzymes, serum cholinesterase (SChE), micronucleus assay and some haematological parameters were used as biomarkers in this study. A statistically significant (P < 0.001) increase in levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase was detected in exposed workers with respect to the control group. There was a significant (P < 0.001) decrease in the level of SChE in the exposed group. Exposed individuals exhibited cytogenetic damage with increased frequencies (P < 0.001) of binucleated cells with micronuclei and total number of micronuclei in binucleated lymphocytes in comparison with subjects of the control group. A decrease (P < 0.001) in cytokinesis block proliferation index similarly demonstrates a genotoxic effect due to pesticide exposure. The results indicate that the pesticide industry workers have experienced significant genotoxic exposure. This study highlights the risk to workers in the pesticide manufacturing industries of developing countries such as Pakistan and the need for implementation of suitable safety measures to prevent/limit exposure to harmful toxins.

Reproductive outcomes in DDT applicators

OBJECTIVES

To explore reproductive outcomes in relation to occupational exposure to DDT.

METHODS

We inquired into the reproductive history, including total number of children, sex distribution in the offspring, time-to-pregnancy, and number of spontaneous abortions and stillbirths, of the spouses of 105 men first exposed to DDT in a 1946-1950 anti-malarial campaign in Sardinia, Italy. The time-to-pregnancy in months at the first successful conception was estimated from population Registrars. Cumulative DDT exposure during the anti-malarial campaign was retrospectively estimated.

RESULTS

The stillbirth rate was elevated and the male/female ratio in the offspring was reversed among DDT-exposed workers, and particularly among DDT applicators, compared to the unexposed subjects. Among DDT applicators, the stillbirth rate increased and the male/female ratio decreased by the tertile of cumulative DDT exposure. The fecundity ratio among spouses of DDT applicators was 0.72 (95% CI, 0.41,1.21) compared to the unexposed. The average number of children and abortion rate were unaffected by DDT exposure.

CONCLUSIONS

The low statistical power of our study does not allow definitive conclusions. However, the results prompt further in-depth research into adverse reproductive outcomes and reduced fertility among men heavily exposed to DDT.

Pesticides and children

Prevention and control of damage to health, crops, and property by insects, fungi, and noxious weeds are the major goals of pesticide applications. As with use of any biologically active agent, pesticides have unwanted side-effects. In this review, we will examine the thesis that adverse pesticide effects are more likely to occur in children who are at special developmental and behavioral risk. Children's exposures to pesticides in the rural and urban settings and differences in their exposure patterns are discussed. The relative frequency of pesticide poisoning in children is examined. In this connection, most reported acute pesticide poisonings occur in children younger than age 5. The possible epidemiological relationships between parental pesticide use or exposure and the risk of adverse reproductive outcomes and childhood cancer are discussed. The level of consensus among these studies is examined. Current concerns regarding neurobehavioral toxicity and endocrine disruption in juxtaposition to the relative paucity of toxicant mechanism-based studies of children are explored.

Health Effects of Chronic Pesticide Exposure: Cancer and Neurotoxicity

Pesticides are widely used in agricultural and other settings, resulting in continuing human exposure. Epidemiologic studies indicate that, despite premarket animal testing, current exposures are associated with risks to human health. In this review, we describe the routes of pesticide exposures occurring today, and summarize and evaluate the epidemiologic studies of pesticide-related carcinogenicity and neurotoxicity in adults. Better understanding of the patterns of exposure, the underlying variability within the human population, and the links between the animal toxicology data and human health effects will improve the evaluation of the risks to human health posed by pesticides. Improving epidemiology studies and integrating this information with toxicology data will allow the human health risks of pesticide exposure to be more accurately judged by public health policy makers.

Cytogenetic biomonitoring of a floriculturist population in Italy: micronucleus analysis by fluorescence in situ hybridization (FISH) with an all-chromosome centromeric probe

Flower production in greenhouses associated with a heavy use of pesticides is very wide-spread in the western part of the Ligurian region (Italy). The formation of micronuclei in peripheral blood lymphocytes is a valuable cytogenetic biomarker in human populations occupationally exposed to genotoxic compounds. In the present study we investigated the micronucleus frequency in peripheral blood lymphocytes of 52 floriculturists and 24 control subjects by use of the cytokinesis-block methodology associated with fluorescence in situ hybridization with a pan-centromeric probe that allowed to distinguish centromere-positive (C+) and centromere-negative (C-) micronuclei. The comparison between floriculturists and controls did not reveal any statistically significant difference in micronucleus frequency, although an increase was observed with increasing pesticide use, number of genotoxic pesticides used and duration of exposure. An increase in C+ as well as in C- micronuclei and in the percentage of C+ micronuclei with respect to the total number of micronuclei was detected in floriculturists, suggesting a higher contribution of C+ micronuclei in the total number scored. The percentage C+ micronuclei was not related to the duration of exposure or to the number of genotoxic pesticides used, but a higher percentage (66.52% versus 63.78%) was observed in a subgroup of subjects using benzimidazolic compounds, compared with the floriculturist population exposed to a complex pesticide mixture not including benzimidazolics. These results suggest a potential human hazard associated with the exposure to this class of aneuploidy-inducing carcinogens.

The use of pesticides in a Polish rural population and its effect on birth weight

INTRODUCTION

The risk of adverse reproductive outcomes related to pesticide exposure has been investigated in few studies; however, the results have not been consistent. The goal of the present study was to evaluate the influence of maternal residual exposure to pesticides on birth weight among women in an agricultural district in Central Poland.

METHOD

Subjects included 104 women who delivered a single, live infant between 1 January 1994 and 31 December 2000. Based on maternal reports, the type of farming (crops, orchards, non-farming jobs), involvement in field work and the trade names of pesticides used within last pregnancy were established. Birth weight for the most recent pregnancy was abstracted from the medical data of the local maternity unit.

RESULTS

Mothers who reported involvement in field work had a similar pregnancy duration but delivered infants with a significantly higher birth weight than mothers not reporting such activities in the first or second trimester of pregnancy (P=0.04). However, after controlling for pregnancy duration and other factors affecting birth weight, we found that maternal exposure to synthetic pyrethroids in the first or second trimester was associated with a small but statistically significant decrease in birth weight (P=0.02).

CONCLUSIONS

We postulate that the observed effect of pyrethroids exposure was related to a slower pace of foetal development corresponding to the small-for-gestational-age (SGA) birth.

Environmental risk factors and male fertility and reproduction

Several environmental substances and pesticides exert a direct, cytotoxic effect on male germ cells. However, an increasing concern has been raised by compounds that may act through more subtle mechanisms, for example, specific pesticides that are potentially capable of modulating or disrupting the endocrine system. Overall, exposure to pesticides with endocrine-disrupting potential raise a particular concern for male fertility because of the possible occurrence of both effects at low concentrations and additive interactions with other environmental risk factors. Delayed reproductive problems deserve special attention, since experimental data consistently indicate a high vulnerability in the developing male reproductive system. Epidemiologic studies have confirmed an increased risk of conception delay associated with occupational exposure to pesticides. Moreover, an increased risk of spontaneous abortion has been noted among wives of exposed workers.

Micronuclei in peripheral blood lymphocytes and buccal epithelial cells of Polish farmers exposed to pesticides

In this biomonitoring study, we investigated whether an occupational exposure to a complex mixture of chemical pesticides produced a significant increase of micronuclei (MN) in both peripheral blood lymphocytes and buccal cells. Forty-nine male workers exposed to pesticides, from an agricultural area of Malopolska Region in Southern Poland, together with 50 men from the same area without indication of exposure to pesticides that served as controls, were used in this investigation. No statistically significant differences in the frequencies of cytogenetic damage were detected between exposed and control individuals, for either type of cells. The multiple linear regression analysis in the case of lymphocytes indicated that the studied cytogenetic endpoints were inversely influenced by alcohol; whilst a negative binomial regression, in the case of buccal cells, indicated that the MN values were directly influenced by the ingestion of red meat. An inverse negative relationship between the cytokinesis-block proliferation index and age, and a significant increase of miscarriages due to the exposure to pesticides were also observed.