Characterization of the t(14;18) BCL2-IGH Translocation in Farmers Occupationally Exposed to Pesticides

Increasing incidence of non-Hodgkin's lymphoma have been associated repeatedly with farming occupation and particular attention focused on the role of pesticide exposure to potentially explain part of this trend. A genetic hallmark of non-Hodgkin's lymphoma is the presence of recurrent chromosomal translocations involving the immunoglobulin heavy chain gene. Of these, the t(14;18), which deregulates BCL2 expression and inhibits apoptosis, is the most frequent in follicular lymphoma and has been detected consistently in peripheral blood lymphocytes of healthy individuals. As BCL2-IGH translocation represents an early step of the malignant process, we evaluated the occurrence and molecular characteristics of BCL2-IGH translocation in 56 individuals occupationally exposed to pesticides in open field farming They were selected from a representative cohort of farmers with a well-defined assessment of pesticide exposure taking into account potential confounding factors, smoking, sunlight, and age. Our results suggest that occupational exposure to pesticides would increase BCL2-IGH prevalence together with the frequency of BCL2-IGH-bearing cells especially during the high pesticide use period. Distribution of BCL2 or IGH breakpoint positions seemed to be independent of pesticide exposure and was similar to those found in other healthy populations or lymphoma patients. Finally, these results provide additional evidence that BCL2-IGH translocation measurements could be a measure of acquired genetic instability in relation to genotoxic exposure in a gene directly relevant in term of lymphomagenesis.

Intoxicações e uso de pesticidas por agricultores do Município de Paty do Alferes, Rio de Janeiro, Brasil

Este trabalho é parte de um estudo mais amplo sobre as conseqüências para a saúde da exposição a pesticidas. Em 1997, no Município de Paty do Alferes, Rio de Janeiro, 55 agricultores foram entrevistados sobre o uso de pesticidas, equipamentos de proteção e medidas de higiene, ocorrência de intoxicações, destino das embalagens vazias e o tipo de orientação técnica recebida pelos usuários destes produtos. Os pesticidas mais usados foram inseticidas como a abamectina, os compostos organofosforados e os piretróides, e os fungicidas como o mancozeb, o clorotalonil e produtos à base de cobre. Entre os trabalhadores envolvidos no preparo e/ou aplicação de pesticidas, 92% informaram não usar qualquer tipo de equipamento de proteção individual. 62% dos agricultores entrevistados informaram já ter "passado mal" ao preparar ou aplicar pesticidas. Os sintomas mais freqüentemente citados foram dor de cabeça, enjôo, vômitos, vertigem, irritação da pele e visão embaçada. Destes agricultores, 21% necessitaram de assistência médica e em mais da metade dos casos (51%), em que os lavradores identificaram os pesticidas que usavam quando "passaram mal", foram citados inseticidas organofosforados da classe toxicológica I.

Pesticides in Lebanon: a knowledge, attitude, and practice study

Pesticides, despite their known toxicity, are widely used in developing countries. Evaluating the pattern of their use would be interesting to assess the appropriateness of adequate intervention. Using a standardized questionnaire, a knowledge, attitude, and practice study was performed in two Lebanese regions, in which a group of agricultural workers was compared to workers of the general population and a third group of pesticide distributors. Agricultural workers were exposed to pesticides during cropping, mixing, loading, and application (100%). They had low pesticide knowledge scales compared to pesticide distributors and to the general population workers (P<10(-7)). The preventive measures they took were low, and the lower their knowledge was, the lower were the preventive measures applied (P<10(-3)). Pesticide safety education is necessary in order to induce protective behavior among agricultural workers. The general population may also benefit from increasing their awareness regarding pesticides.

Acute occupational pesticide-related illness in the US, 1998-1999: surveillance findings from the SENSOR-pesticides program

BACKGROUND

Concern about the adverse public health and environmental effects of pesticide use is persistent. Recognizing the importance of surveillance for acute occupational pesticide-related illness, we report on surveillance for this condition across multiple states.

METHODS

Survey data collected between 1998 and 1999 were obtained from the seven states that conduct acute occupational pesticide-related illness surveillance as part of the Sentinel Event Notification System for Occupational Risks (SENSOR) program. Data were collected by these state programs in a standardized manner and analyzed. Acute occupational pesticide-related illness incidence rates for those employed in agriculture and those employed in non-agricultural industries were also calculated.

RESULTS

Between 1998 and 1999, a total of 1,009 individuals with acute occupational pesticide-related illness were identified by states participating in the SENSOR-pesticides program. The mean age was 36 years, and incidence rates peaked among 20-24 year-old workers. The overall incidence rate was 1.17 per 100,000 full time equivalents (FTEs). The incidence rate among those employed in agriculture was higher (18.2/100,000 FTEs) compared to those employed in non-agricultural industries (0.53/100,000 FTEs). Most of the illnesses were of low severity (69.7%). Severity was moderate in 29.6% of the cases, and high in four cases (0.4%). Three fatalities were identified. Insecticides were responsible for 49% of all illnesses.

CONCLUSIONS

Surveillance is an important tool to assess acute pesticide-related illness, and to identify associated risk factors. Our findings suggest that these illnesses continue to be an important occupational health problem, especially in agriculture. As such, greater efforts are needed to prevent acute occupational pesticide-related illness.

[Current use of pesticides in Poland and the risk of reproductive disorders]

Among numerous factors typical of occupations in agriculture, pesticides occupy a specific place. Their hazardous effects may be manifested among others by reproductive disorders. Therefore, it is very important to know what kind of pesticides is used in both agriculture and greenhouses. The aim of the study was to review the kinds and amounts of pesticides used in agriculture and greenhouses. The review was performed in the Kujawsko-pomorskie voivoship and on 14 horticulture farms. Their selection was based on the register of the Polish Horticulture Chamber. The pesticides were classified into two groups: those containing reproductive and/or developmental toxins (RD) and those acting as endocrine disrupters (ED). The majority of pesticides used in agriculture and horticulture belong to one of those groups. The results of the review suggest that the awareness of potential adverse effects of pesticides on fertility and pregnancy outcome should be increased among workers occupationally exposed to pesticides.

Pesticide exposure in dwellings near bulb growing fields in The Netherlands: an explorative study

An explorative field study was conducted to assess residential exposure to pesticides, regularly applied in bulb farming. House dust floor samples were taken from homes of bulb farmers (n = 12) and from homes in close proximity to a bulb field (i.e. non-farmers) (n = 15). Samples were analysed for 7 pesticides used by bulb growers in the sampling period. Of these pesticides, chloropropham, flutolanil and vinchlozolin could be detected in non-farmers homes. All pesticides were detected in farmers' homes, except metamitron. Median concentrations for chloropropham were significantly higher in farmers' homes (0.05 vs. 0.20 microg/m(2), p = 0.03). Logistic regression analyses showed that the odds for detecting pesticides were higher in farmers' compared to non-farmers' homes and remained higher after correction for potential confounders. Results showed no significant effect of proximity of a residence to a bulb field for median concentrations of pesticides; however, logistic regression analysis showed a borderline statistically significant effect for detecting chloropropham above the detection limit (OR = 10, p = 0.08). These findings demonstrate that, as expected, risk of exposure is higher for bulb farmers than for non-farmers. They also indicate that exposure to pesticides is not limited to bulb farmers only, and this warrants further investigation.

Cancer risk in offspring of male pesticide applicators in agriculture in Sweden

AIMS

To explore cancer risk from date of birth until 1994 in children, born 1958 or later, of Swedish male pesticide applicators.

METHODS

Records of male pesticide applicators licensed 1965-76 were linked to the Multigeneration Register. The records of their offspring were then linked to the Swedish Cancer Registry and the Cause of Death Register.

RESULTS

In total 51 cases of cancer were observed, which is significantly lower than the expected 73.0 (standardised incidence ratio (SIR) 0.70, 95% CI 0.52 to 0.92). Tumours of the nervous system was most common, amounting to 20 cases, 39% of all cancer cases (SIR 1.01, 95% CI 0.62 to 1.56). A statistically significant reduced risk for leukaemia was found (SIR 0.43, 95% CI 0.19 to 0.86). For non-Hodgkin's lymphoma, three cases were observed and 4.8 expected (SIR 0.63, 95% CI 0.13 to 1.83). For Hodgkin's disease, five cases were observed versus 3.7 expected (SIR 1.36, 95% CI 0.44 to 3.17). Two cases of testicular cancer were observed and 1.7 expected (SIR 1.19, 95% CI 0.13 to 4.28).

CONCLUSIONS

None of the a priori hypotheses of increased risk of tumours of the nervous system, kidney cancer, leukaemia, lymphoma, soft tissue sarcoma, and testicular cancer in children of male pesticide applicators could be confirmed.

Safety Practices, Neurological Symptoms, and Pesticide Poisoning

Depression, anxiety, inability to concentrate, and spatial disorientation associated with pesticide poisoning may influence farmers' ability to comply with established safety procedures. The purpose of this article is to describe the relationship between safety practices, neurological symptoms, and pesticide poisoning. A survey of farm residents was conducted in an eight-county area in Colorado. Multivariate logistic regression models were used to determine associations between safety practices, neurological symptoms, and previous pesticide poisoning. A number of safety practices were associated with the following neurological symptoms: difficulty concentrating; feeling irritable; relatives noticing memory difficulties; and difficulty understanding reading materials. The associations between safety practices and neurological symptoms were increased in the presence of pesticide poisoning. Factors associated with failure to engage in established safety practices in this study were neurological symptoms.

Integrative assessment of multiple pesticides as risk factors for non-Hodgkin's lymphoma among men

BACKGROUND

An increased rate of non-Hodgkin's lymphoma (NHL) has been repeatedly observed among farmers, but identification of specific exposures that explain this observation has proven difficult.

METHODS

During the 1980s, the National Cancer Institute conducted three case-control studies of NHL in the midwestern United States. These pooled data were used to examine pesticide exposures in farming as risk factors for NHL in men. The large sample size (n = 3417) allowed analysis of 47 pesticides simultaneously, controlling for potential confounding by other pesticides in the model, and adjusting the estimates based on a prespecified variance to make them more stable.

RESULTS

Reported use of several individual pesticides was associated with increased NHL incidence, including organophosphate insecticides coumaphos, diazinon, and fonofos, insecticides chlordane, dieldrin, and copper acetoarsenite, and herbicides atrazine, glyphosate, and sodium chlorate. A subanalysis of these "potentially carcinogenic" pesticides suggested a positive trend of risk with exposure to increasing numbers.

CONCLUSION

Consideration of multiple exposures is important in accurately estimating specific effects and in evaluating realistic exposure scenarios.

Occupation related pesticide exposure and cancer of the prostate: a meta-analysis

AIMS

To summarise recent literature on the risk of prostate cancer in pesticide related occupations, to calculate the meta-rate ratio, and to compare it to data from meta-analyses previously published.

METHODS

A meta-analysis of 22 epidemiological studies, published between 1995 and 2001, was conducted in order to pool their rate ratio estimates. Studies were summarised and evaluated for homogeneity and publication bias.

RESULTS

The meta-rate ratio estimate, based on 25 estimators of relative risk from 22 studies, was 1.13 (95% CI 1.04 to 1.22). Significant heterogeneity of rate ratios existed among the different studies. Therefore, a stratified analysis was carried out. Major sources of heterogeneity identified were geographic location, study design, and healthy worker effect. Overall, pooled risk estimates for studies derived from Europe were lower than those derived from the USA/Canada. A significant increase in rate ratio was observed for the occupation category of pesticide applicators, whereas no significant increase was observed for farmers. There was no evidence of publication bias.

CONCLUSION

This increased meta-rate ratio for prostate cancer in different pesticide related occupations, including farmers, is very similar to three, previously published, meta-rate ratios for prostate cancer in farmers calculated from studies published before 1995. Although the underlying data do not identify pesticide exposure as an independent cause for prostate cancer, the fact that an increased meta-rate ratio is again obtained points to occupational exposure to pesticides as a possible factor. Future epidemiological studies should focus, as far as possible, on reliable methods to estimate actual exposure.

[Threats to human health in the use of pesticides (a review)]

The paper presents current trends in the use of pesticides and detection of their residues in the environmental objects. Pesticides are shown to be a serious health risk factor for different groups of the population when they are irrationally used and inadequately stored. A package of measures to prevent intoxication and to reduce a risk for pesticide entry into the body is provided.

[Bronchial asthma in rural environment]

This paper reviews basic problems concerning epidemiology and pathogenesis of bronchial asthma in the rural environment. Possible causes of the decreased prevalence of atopy and allergic diseases are analyzed. Etiology, pathogenesis and clinical findings of asthma-like syndromes, a major problem of differential diagnosis, as well as the principles of occupational asthma diagnostics in farmers are also presented.

Sugarcane farming, occupational solvent exposures, and the risk of oral cancer in Puerto Rico

The work history information from a population-based case-control study conducted in Puerto Rico was analyzed using a job exposure matrix to investigate the relationship between occupational exposures and cancers of the oral cavity or pharynx. After adjustment for age, alcohol, smoking, and residence in a logistic model, the risk for cancer of the oral cavity, but not the pharynx, was significantly elevated among farm workers in the sugarcane industry (OR = 4.4, 95% CI = 1.4-13.6). An exposure-response trend was seen for cumulative exposure to solvents, with an OR = 3.2 (95% CI = 0.8-12.6) in the highest exposure category. The overall contribution to the risk of cancer of the oral cavity or pharynx associated with occupational exposures in Puerto Rico appears to be small, however, the elevated risks were seen among sugarcane farmers and subjects with high cumulative exposure to solvents.

Exposure to animals and selected risk factors among Canadian farm residents with Hodgkin's disease, multiple myeloma, or soft tissue sarcoma

Exposures to farm animals has been associated with certain rare cancers. Simultaneously, using the same methodology and control group, we conducted a six-province incident, population-based study of Hodgkin's disease (HD), multiple myeloma (MM), and soft tissue sarcoma (STS). Farm residence or work was reported by 38% (n = 119) of HD, 45% (n = 178) of MM, 43% (n = 156) of STS cases and 45% (n = 673) of controls. We conducted conditional logistic regression analyses and report odds ratios (OR(adj)) and 95% confidence intervals. After adjustment for covariates, exposure to farm animals had minimal effect on risk. The independent risk factors after adjustment for covariates were a family history of cancer (MM, STS), occupational uranium exposure (HD), professional driving (MM), and personal previous cancer (MM) or shingles (HD, MM).

[Rural work and risk factors associated with pesticide use in Minas Gerais, Brazil]

This paper aimed to characterize the rural work process in nine counties in Minas Gerais State, considering socio-demographic indicators, the land tenure structure of farm operations, and work practices related to pesticide use and poisoning Data were obtained through the Jorge Duprat Figueiredo Foundation for Workers' Safety and Occupational Medicine, which applied a questionnaire to 1,064 rural workers from 1991 to 2000. Through a logistic regression, risk factors associated with pesticide poisoning were obtained for the carbamate and organophosphate groups. Some 50% of interviewees displayed at least moderate pesticide toxicity. Risk factors for pesticide poisoning were: last contact with pesticides less than two weeks before the blood cholinesterase test; no use of personal protective equipment by workers applying pesticides; having received instructions from the pesticide salesperson; report of carbamates/organophosphates as the main pesticides used; and working in the counties of Te foli Otoni, Guidoval, or Piraúba. The results emphasize the high level of health risk associated with pesticide use among these rural workers.

[Cytogenetic alterations in field workers routinely exposed to pesticides in Bogota flowers farms]

Frequency of cytogenetic alterations (micronuclei and chromosome aberrations), DNA repair deficiencies and acetylcholinesterase activity was determined for field workers in Bogotá, Colombia. These workers were regularly exposed to organophosphate and carbamate insecticides while employed on farms for flower growing. Interviews were conducted with 31 workers associated with occupational risk of pesticides exposure and 30 without exposure. A standard cytogenetic assay was used to determine chromosome aberrations and micronuclei frequencies. In addition, a challenge assay assessed response to gamma-rays as an indication of DNA repair deficiencies--cells were exposed to gamma-rays in vitro and the frequencies of chromosome aberrations in post-irradiation metaphase cells were quantified. The data were evaluated for percentage of aberrant cells, cells with chromosome aberrations and frequencies of chromatid breaks per 100 metaphase cells in each worker. The exposed group had a significantly higher frequency of cells with chromosome aberrations and micronuclei as compared with the non-exposed group (p = 0.02). However, the challenge assay did not indicate a significant difference (p > 0.1). These findings require confirmation by further analytical studies involving larger sample. Cytogenetic and toxicological studies, in conjunction with thorough clinical examination are recommended.

Chronic fatigue and organophosphate pesticides in sheep farming: a retrospective study amongst people reporting to a UK pharmacovigilance scheme

The Department of Health has recently published a report from the CFS/ME Working Group which concluded that chronic fatigue syndrome (CFS) should be recognized as a chronic illness. Symptoms consistent with CFS are often reported by people who consider their health has been affected by exposure to pesticides, but the Working Group concluded that this type of exposure is not a common trigger for the syndrome. The Veterinary Medicines Directorate (VMD) collects self-assessed reports of ill health in humans associated with veterinary medicines under their Suspected Adverse Reaction Surveillance Scheme. The reporters have mainly been sheep farmers. These reports were used to investigate the possible relationship between chronic fatigue (CF) and exposure to organophosphate pesticides in sheep farming. The overall aim of the study was to investigate a possible association between exposure to organophosphates and the development of CF amongst people who consider their health has been affected by pesticides in sheep farming. The hypothesis investigated was that repeated exposure to organophosphate pesticides in sheep dip may increase the probability of developing CF. A group of mostly sheep farmers who had reported to the VMD surveillance scheme were identified. We planned to use a retrospective case-control study design but the initial symptoms reports were not sufficiently reliable to enable this. The study population was asked to complete two questionnaires. The first questionnaire was designed to identify the history of exposure of subjects to organophosphate pesticides, and their exposure was then reconstructed using a metric specifically developed for this purpose. The second questionnaire collected detailed information to identify whether the subjects had CF when they originally reported to the VMD and at the time of the survey. The questionnaire was sent to a total of 206 subjects, of whom 28 had moved home. A total of 37% of the remaining 178 subjects participated. There was a high prevalence of CF amongst those who completed the questionnaire and this has generally persisted since the subjects reported to the VMD. Higher CF scores were associated with higher exposure to organophosphate pesticides. CF is very common amongst those who consider their health was affected by pesticides and we have shown there is limited evidence of an association between exposure to organophosphates and CF. Further research is needed to investigate the cause of this syndrome amongst farmers exposed to pesticides.

Shade tobacco and green tobacco sickness in Connecticut

The prevalence of Green Tobacco Sickness (GTS) among shade tobacco farmworkers in Connecticut is unknown. We conducted a study to determine the prevalence of GTS in farmworkers working in shade tobacco fields who presented for clinical care at medical student-run clinics. A retrospective chart review of the tobacco workers seen at Farmworkers' Clinics during 2001 was instituted in this study. Although GTS was not clinically diagnosed in any of the patients, we found 15% diagnoses that could be attributed to possible GTS by ICD-9 code review. Using a stricter GTS case definition, the frequency rate decreased to 4%. Nonsmokers were significantly more likely than smokers to report GTS-like symptoms (P < 0.01). Isolated symptoms of headache and dizziness were significantly more frequent among nonsmokers than smokers (P < 0.05). In conclusion, cases of possible GTS were found in Connecticut shade tobacco workers. Nonsmokers were more at risk to have possible GTS than smokers.

Farm pesticides: outcomes of a randomized controlled intervention to reduce risks

BACKGROUND

In response to the multiple health risks that farm pesticide applicators experience and the need for controlled trials to evaluate prevention programs, this study tested the effects of a small-group educational intervention designed to increase personal protective equipment (PPE) use and to reduce direct pesticide exposure.

DESIGN

A randomized controlled design was used with random selection of participants, random assignment to intervention and control groups, and baseline and postintervention assessments.

SETTING/PARTICIPANTS

Four hundred Wisconsin dairy farmers certified to apply pesticides to field crops were recruited to participate over a 1-year evaluation period.

INTERVENTION

Three-hour educational sessions were conducted with approximately 100 randomly assigned participants. Sessions targeted four educational messages: (1) existing evidence of excess cancers among farmers, (2) simulation of pesticide exposure presented through slide show and description, (3) feedback of self-reported data collected from the farmers reporting on frequency of exposure and gear use, and (4) cognitive behavioral strategies that can be adopted to reduce pesticide hazards.

MAIN OUTCOME MEASURES

A change in use of required protective equipment use during application and self-reported dermal exposure were evaluated in the control and intervention groups postintervention.

RESULTS

Six-month postintervention analyses showed that an educational intervention had significant effects on the use of gloves and gear during the most recent application and an actual reduction in the total number of pesticides used. However, the intervention did not have a significant impact on achieving full PPE compliance nor in reducing the amount of self-reported dermal pesticide exposure during the most recent application reported by applicators. CONCLUSIONS; This one-time educational intervention successfully increased protective equipment use. However, more-intensive programs are needed to achieve greater reductions in personal pesticide exposure.

Use of agricultural pesticides and prostate cancer risk in the Agricultural Health Study cohort

The authors examined the relation between 45 common agricultural pesticides and prostate cancer incidence in a prospective cohort study of 55,332 male pesticide applicators from Iowa and North Carolina with no prior history of prostate cancer. Data were collected by means of self-administered questionnaires completed at enrollment (1993-1997). Cancer incidence was determined through population-based cancer registries from enrollment through December 31, 1999. A prostate cancer standardized incidence ratio was computed for the cohort. Odds ratios were computed for individual pesticides and for pesticide use patterns identified by means of factor analysis. A prostate cancer standardized incidence ratio of 1.14 (95% confidence interval: 1.05, 1.24) was observed for the Agricultural Health Study cohort. Use of chlorinated pesticides among applicators over 50 years of age and methyl bromide use were significantly associated with prostate cancer risk. Several other pesticides showed a significantly increased risk of prostate cancer among study subjects with a family history of prostate cancer but not among those with no family history. Important family history-pesticide interactions were observed.

Acute pesticide-related illnesses among working youths, 1988-1999

OBJECTIVES

The goal of this study was to describe acute occupational pesticide-related illnesses among youths and to provide prevention recommendations.

METHODS

Survey data from 8 states and from poison control center data were analyzed. Illness incidence rates and incidence rate ratios were calculated.

RESULTS

A total of 531 youths were identified with acute occupational pesticide-related illnesses. Insecticides were responsible for most of these illnesses (68%), most of which were of minor severity (79%). The average annual incidence rate among youths aged 15 to 17 years was 20.4 per billion hours worked, and the incidence rate ratio among youths vs adults was 1.71 (95% confidence interval = 1.53, 1.91).

CONCLUSIONS

The present findings suggest the need for greater efforts to prevent acute occupational pesticide-related illnesses among adolescents.

Neurobehavioural effects among workers occupationally exposed to organophosphorous pesticides

AIMS

To identify neurobehavioural deficits among workers exposed to organophosphorous (OP) pesticides in their occupation.

METHODS

This study was conducted during the period when pesticides were applied to cotton crops in the fields in Menoufiya Governorate, Egypt. Fifty two occupationally exposed male workers were compared to 50 unexposed male controls who were similar in age, socioeconomic class, and years of education (> or =12 years). All participants completed a questionnaire (assessing personal, occupational, and medical histories), general and neurological clinical examination, neurobehavioural test battery (including tests for verbal abstraction, problem solving, attention, memory, and visuomotor speed), personality assessment, and serological analysis for serum acetylcholinesterase.

RESULTS

After correcting for confounders of age and education, the exposed participants exhibited significantly lower performance than controls on six neurobehavioural tests (Similarities, Digit Symbol, Trailmaking part A and B, Letter Cancellation, Digit Span, and Benton Visual Retention). A longer duration of work with pesticides was associated with lower performance on most neurobehavioural tests after adjusting for multiple comparisons. Although serum acetylcholinesterase was significantly lower in the exposed than the control participants, it was not significantly correlated with either neurobehavioural performance or neurological abnormalities.

CONCLUSIONS

Occupational exposure to OP pesticides was associated with deficits in a wider array of neurobehavioural functions than previously reported, perhaps because of higher exposure in this population. Moderate chronic OP exposure may not only affect visuomotor speed as reported previously, but also verbal abstraction, attention, and memory.

An investigative report on circumstances leading to death among Indian cotton farmers

Andhra Pradesh, a southern state of India has been in the news for cotton farmers' deaths/suicides since 1998. The occurrence of 12 deaths among the farmers in the years 2001-2002 clustering around September-October expedited the investigation. The objective of our investigation was to identify the circumstances leading to death of cotton farmers in Warangal district of Andhra Pradesh. Some of the broadly held hypotheses were also analyzed for their validity. The socioeconomic-political factors emerge as very strong determinants of deaths, given the occupational work environment.

Neurodegenerative diseases and exposure to pesticides in the elderly

The authors investigated the hypothesis that exposure to pesticides could be related to central nervous system disorders in a prospective cohort study of 1,507 French elderly (1992-1998). Lower cognitive performance was observed in subjects who had been occupationally exposed to pesticides. In men, the relative risks of developing Parkinson's disease and Alzheimer's disease for occupational exposure assessed by a job exposure matrix were 5.63 (95% confidence interval: 1.47, 21.58) and 2.39 (95% confidence interval: 1.02, 5.63), respectively, after confounding factors were taken into account. No association was found with having a primary job in agriculture or with environmental pesticide exposure, nor was an association found in women. These results suggest the presence of neurologic impairments in elderly persons who were exposed occupationally to pesticides.

National Health Interview Survey mortality among US farmers and pesticide applicators

BACKGROUND

The mortality experience of pesticide-exposed workers across the US has not been thoroughly studied.

METHODS

Cox regression mortality analyses adjusted for the complex sample survey design were performed on mortality-linked 1986-1994 National Health Interview Survey (NHIS) data.

RESULTS

Nine thousand four hundred seventy-one farmers and pesticide applicators with 571 deaths were compared to 438,228 other US workers with 11,992 deaths. Age-adjusted risk of accidental death, as well as cancers of the nervous and lymphatic/hematopoietic systems, was significantly elevated in male and female pesticide-exposed workers; breast, prostate, and testicular cancer mortality risks were not elevated.

CONCLUSIONS

Compared to all other workers, farmers and pesticide applicators were at greater risk of accidental mortality. These pesticide-exposed workers were not at an increased risk of cancers possibly associated with exposure to estrogen analogue compounds, but were at an increased risk of hematopoietic and nervous system cancers. NHIS mortality follow-up represents an important occupational health surveillance instrument.

Sunscreens can increase dermal penetration of 2,4-dichlorophenoxyacetic acid

Agricultural workers are encouraged to wear sunscreen to reduce their risk of skin cancer. These workers are also exposed to herbicides during the course of their day. The skin is the major source of chemical exposure in agriculture. The purpose of this work is to determine the effect of sunscreen use on the transdermal absorption of a model herbicide, 2,4-dichlorophenoxyacetic acid. Hairless mouse skin was pretreated with one of nine commercially available sunscreens purchased at a local drug store. The herbicide 2,4-dichlorophenoxyacetic acid was placed on top of the epidermis in an in vitro diffusion chamber for 24 hours. The total penetrating through the skin in 24 hours ranged from 39.1 +/- 1.7% for the no sunscreen control to 81.0 +/- 2.8% for Neutrogena Oil Free Sunscreen. Of the nine sunscreens tested, six led to a significant enhancement of total 2,4-dichlorophenoxyacetic acid penetration as compared to the control (p < 0.01). Careful selection of sunscreen during pesticide application could reduce potential exposure.

[Fertility and occupational exposure to pesticides]

The epidemiological studies discussed in this paper are concerned with the association between exposure to pesticides among workers employed in agriculture or greenhouses and pregnancy and semen quality. The results of the studies showed that employment in agriculture increases the risk of specific morphological abnormalities in sperm as well as decreases the sperm count and the percentage of viable sperm. The data on the effect of employment in agriculture on the time of pregnancy are not unequivocal, but most of them suggest the relationship between pesticide exposure and decreased fecundity rate. The studies of the gender ratio of the offspring do not yield explicit results showing that more girls than boys are born to workers exposed to pesticides. The results of the literature review also suggest the need to increase the awareness about potential adverse effects of pesticides on fertility among workers occupationally exposed to them. In the light of the available, alas still insufficient evidence that pesticides exert negative effect on fertility, it is essential to reduce pesticide exposure both among men and women before the planned pregnancy.

[Occupational hygiene during pesticide use]

The study covered assortment and amount of pesticides varying in purpose and chemical class and applied in Saratov region in 2002 vs in 1980s and 1990s. Findings are changed assortment, occurrence of new generation pesticides, significantly lower pesticide load, and seed mordants predominant over other pesticide groups. These findings necessitate special attention to occupational hygiene for health preservation among rural agricultural workers.

[Most frequent causes of allergic contact dermatitis in farmers: based on material collected in the Nofer Institute of Occupational Medicine, Lodz]

Farmers are exposed to many skin damaging factors. Following dermatological and allergological examinations, in a group of 132 farmers with suspected occupational disease, contact allergy induced by metals (chromates, nickel, cobalt, mercury), disinfectants and their components (formaldehyde, glutaraldehyde, quaternary ammonium compounds, lysol, chloramine), rubber and pesticides, especially pesticides of thiophtalimide and thiocarbamate groups were recorded. Farmers also reacted to other chemical compounds (colophony, lanolin, propolis) rarely responsible for hypersensitivity in other occupational groups. In addition, extensive areas of dermatitis (13%) induced by irritating chemical (fertilizers, pesticides, fodder for breeding animals) and physical (changing temperature, humidity, effect of solar radiation) factors were observed in the study group.

Work with pesticides and organophosphate sheep dips

Pesticides are an important hazard in agriculture. In developed countries their use is strictly regulated. Risk assessment for new pesticides includes comparison of the potential exposures of spray operators and other farm workers with a reference value. Usually, this is derived from toxicological studies in animals with allowance for the uncertainties in extrapolating between and within species. Older pesticides undergo periodic reviews, for which epidemiological data may also be available. Unintentional fatal poisoning by pesticides is extremely rare in Britain. Documented reports of non-fatal acute poisoning are also uncommon, but there may be substantial under-ascertainment of minor incidents. Pesticides have been linked with various chronic diseases, but few associations have been clearly established. A particular concern recently in Britain has been the possibility that organophosphate insecticides can cause chronic neuropsychiatric illness.

Micronucleus monitoring of a floriculturist population from western Liguria, Italy

A biomonitoring study was carried out to investigate whether exposure to complex pesticide mixtures in ornamental crop production represents a potential genotoxic risk. Exposed and control subjects were selected in western Liguria (Italy). The area was chosen for its intensive use of pesticides. The main crops produced were roses, mimosas, carnations and chrysanthemums, as ornamental non-edible plants, and tomato, lettuce and basil, as edible ones. The levels of micronuclei (MN) were analysed in peripheral blood lymphocytes of 107 floriculturists (92 men and 15 women) and 61 control subjects (42 men and 19 women). A statistically significant increase in binucleated cells with micronuclei (BNMN) was detected in floriculturists with respect to the control population (4.41 +/- 2.14 MN/1000 cells versus 3.04 +/- 2.14, P < 0.001). The mean number of BNMN varied as a function of sex and age. Smoking habit had no effect on MN frequency. A positive correlation between years of farming and MN frequency in peripheral blood lymphocytes was observed (r = 0.30, P = 0.02). The conditions of exposure were also associated with an increase in cytogenetic damage, with a 28% higher MN frequency in greenhouse workers compared with subjects working only outdoors in fields. Workers not using protective measures during high exposure activities showed an increase in MN frequency. Our findings suggest a potential genotoxic risk due to pesticide exposure.

[End-stage renal disease among patients in a referral hospital in El Salvador]

OBJECTIVE

El Salvador is a country with high mortality from end-stage renal disease (ESRD). The objective of this study was to determine the epidemiological characteristics of a series of new cases of ESRD seen in a referral hospital in the country.

METHODS

A cross-sectional study was conducted of all the new cases that initiated chronic dialysis between November 1999 and March 2000. Using a personal interview, data were obtained on the patients' clinical, demographic, and occupational characteristics, among others.

RESULTS

During the five months that the study lasted, 205 new cases of ESRD were observed. Among the 202 interviewees, two groups were clearly distinguished. One group, of 67 patients (33%), had known risk factors for ESRD, similar to those for developed countries (basically, diabetes mellitus, hypertension, and chronic consumption of non-steroidal anti-inflammatories). Another group of 135 patients (67%) had unusual characteristics that were not associated with the known risk factors. The majority of the patients in this second group were male, farmers, residents of coastal areas or areas next to rivers, and some years before had been exposed, without adequate protection, to agricultural insecticides or pesticides through their work.

CONCLUSIONS

We have identified an important group of patients with ESRD who seem to lack a cause for their disease. Their special characteristics make it possible to suspect a relationship with the occupational exposure to insecticides or pesticides. New studies are needed in order to confirm this hypothesis.

Pesticide poisoning and depressive symptoms among farm residents

PURPOSE

The purpose of the study presented is to evaluate the association between pesticides and depressive symptoms among a population exposed to chemicals as a result of agricultural use. Chronic sequelae of acute pesticide poisoning from organophosphate compounds may include anxiety and depression. In some states, farmers have been reported to have higher rates of depression than other population groups. Little work has been done to describe the effects of exposure to organophosphate compounds and depressive symptoms among the farming population.

METHODS

Data for this study came from a cross sectional survey of farmers and their spouses conducted in an eight county area in northeastern Colorado. Personal interviews were conducted with the study participants. Depressive symptoms were assessed using the Center for Epidemiologic Studies-Depression (CES-D) scale. Pesticides applied on the farms were assessed using self-reported questionnaires. Conditional logistic regression was used to model the relationship between depression and pesticide-related illness in a stratified analysis.

RESULTS

Between 1992-1997, 761 individuals were enrolled in this cross sectional survey. Adjusting for a number of potential confounders, the odds ratio for depression associated with pesticide-related illness was 5.87 [95% confidence interval (CI) = 2.56-13.44].

CONCLUSIONS

Exposure to pesticides at a high enough concentration to cause self reported poisoning symptoms was associated with high depressive symptoms independently of other known risk factors for depression among farm residents.

Clinical validation of methods of diagnosis of neuropathy in a field study of United Kingdom sheep dippers

OBJECTIVES

To investigate the reproducibility of measured indices of chronic peripheral neuropathy from a field study of sheep dippers when compared with similar measurements carried out in a clinical setting.

METHODS

A stratified random sample of field study subjects was invited to attend a clinic. Neuropathy was measured both in the field and at the clinic with a modified version of a standard symptoms questionnaire and quantitative sensory thresholds for hot, cold, and vibration. These were combined into a classification of the likelihood of neuropathy with a neuropathy scoring system. Indicators of sensory abnormality were based on comparison of sensory thresholds to age dependent reference values derived from an external reference group.

RESULTS

Only 51% of subjects were assigned similar classifications in the field and clinic based on the neuropathy scoring system. Of the component indices, grouped symptom scores, with 65% of subjects showing exact agreement, proved to be more reproducible than quantitative sensory test indicators. There were biases in the comparison of field and clinic measurements of hot and vibration sensations, but no evidence of greater variation between individual people in sensory thresholds in the field relative to at the clinic.

CONCLUSIONS

The neuropathy scoring system proved to be of limited reproducibility, due in a large part to the lack of reproducibility of the indicators of sensory test abnormality caused by inadequate temperature control. However, the symptoms score and measured sensory thresholds could be used separately as indices of neuropathy in exposure-response analyses.

Occupational risk factors for renal cell cancer. An Italian case-control study

AIM

To examine possible associations between occupational and environmental risk factors and renal cell cancer (RCC), a tumour with unclear aetiology and increasing incidence.

METHODS

A questionnaire-based case-control study of 100 histologically verified cases of RCC and 200 controls was conducted at Parma University Hospital. The control group was enrolled from patients attending different outpatient departments and represented the same residential area as the cases. For all exposure variables under study, two levels of duration were defined: "short" and "prolonged" for less than 10 years or more, respectively.

RESULTS

The highest risk estimates for RCC were found for "prolonged" exposure to organic solvents with an odds ratio (OR) of 2.2 (95% confidence interval, CI: 1.0-4.8). "Prolonged" exposures to pesticides and copper sulphate were also associated with increased risk, OR 2.0 (95% CI: 0.8-4.7) and OR 2.7 (95% CI: 1.3-5.5), respectively.

CONCLUSIONS

Our data suggests an association between RCC and exposure to organic solvents, pesticides and copper sulphate. A risk gradient as a function of exposure duration was found for organic solvents (p = 0.044) and copper sulphate (p = 0.036), but not for pesticides.

A clinical neurological, neurophysiological, and neuropsychological study of sheep farmers and dippers exposed to organophosphate pesticides

OBJECTIVES

To classify clinical diseases of the subjects with abnormal indices of peripheral neuropathy identified in field studies of sheep farmers and dippers exposed to organophosphate pesticides. To explore what neuropsychological profiles, if any, may be associated with neurophysiological damage in these subjects.

METHODS

A case-control study (79 subjects) nested within the cross sectional study (685 subjects) of sheep farmers from the field study. Three groups with no, possible, and probable or definite neuropathy according to field studies were recruited. Investigations comprised symptoms of neuropathy, neurologial signs, motor and sensory nerve conduction, electromyography, quantitative sensory testing, and neuropsychological tests.

RESULTS

The incidence of clinical neuropathy increased from 7% in the no neuropathy group to 52% in the probable or definite neuropathy group based on nerve conduction measurements or presence of neurological signs. Sensory abnormalities were found more often than motor deficits. Small diameter nerve fibres were also affected more than large fibres.

CONCLUSIONS

The neuropathy is predominantly sensory and is characteristic of distal, chronic neuropathy with no acute features. Small fibre populations are affected more than large fibre populations. Increasing severity of neuropathy was associated with anxiety and depression as measured in the neuropsychological tests.

Knowledge, attitude, practice, and toxicity symptoms associated with pesticide use among farm workers in the Gaza Strip

AIMS

To assess knowledge, attitude, practice, and toxicity symptoms associated with pesticide use and exposure among 189 farm workers in the Gaza Strip.

METHODS

A cross section of agricultural farm workers in the Gaza Strip were asked to fill in a questionnaire on knowledge, attitudes, practice towards pesticide use, and associated toxicity symptoms.

RESULTS

Farm workers reported high levels of knowledge on the health impact of pesticides (97.9%). Moderate to high levels of knowledge were recorded on toxicity symptoms related to pesticides. Most farm workers were aware of the protective measures to be used during applying pesticides. However, no one took precautions unless they knew about the measures. Burning sensation in eyes/face was the commonest symptom (64.3%). The prevalence of self reported toxicity symptoms was dependent on mixing and use of high concentrations of pesticides. The highest percentage of self reported toxicity symptoms was found among the farm workers who returned to sprayed fields within one hour of applying pesticides.

CONCLUSIONS

Farm workers in the Gaza Strip used pesticides extensively. Despite their knowledge about the adverse health impact of the pesticides, the use of protective measures was poor. Most had self reported toxicity symptoms, particularly the younger workers. It would be useful to minimise the use of pesticides and encourage alternative measures. Prevention and intervention programmes regarding the use of protective measures and monitoring the health status of farm workers should be implemented.