National Health Interview Survey mortality among US farmers and pesticide applicators

Interaction of organophosphate pesticide chlorpyrifos with alpha-2-macroglobulin: Biophysical and molecular docking approach

Organophosphate class of pesticides causes neurotoxicity and carcinogenicity in humans. Once inside the human body, these pesticides often interact with plasma proteins, such as alpha-2-macroglobulin (α₂M) which is the key anti-proteinase. Our work focuses on the structural and functional alteration of α₂M by chlorpyrifos (CPF), a member of organophosphates. We explored the binding interaction between alpha-2-macroglobulin and CPF by using UV absorption and fluorescence spectroscopy (steady state and synchronous), circular dichroism and molecular docking approach. The functional activity of α₂M was analyzed by anti-proteinase trypsin inhibitory assay which showed dose-dependent decrease in alpha-2-macroglobulin antiproteolytic potential. UV absorption studies and fluorescence quenching experiments suggested the formation of a complex between α₂M and CPF. The CD spectra suggested a reduction in the beta helical (β helix) content of α₂M. Analysis of thermodynamic parameters suggested the process is spontaneous and endothermic with the ΔG and ΔH values being -5.501 kJ/mol, 11.49 kJ/mol, respectively. CPF binds with Ile-1390, Pro-1391, Leu-1392, Lys-1393, Val-1396, Lys-1397, Arg-1407, Thr-1408, Glu-1409, Val-1410, Asp-282, Glu-281 of α₂M as suggested by molecular docking.

Clinical profile and outcome of acute organophosphate poisoning in children of Upper Egypt: a cross-sectional study

Background

Organophosphates are one of the most common agents of poisoning in developing countries including Egypt. Due to lack of data about characteristics of organophosphates poisoning in our localities, we aimed to evaluate its clinical pattern and factors affecting outcome.

Methods

It was a cross-sectional study conducted in South valley University hospital between January 2019 and December 2019. It included all children ≤16 years of age presented with organophosphates poisoning. Diagnosis was performed from the history taken from the patient’s relatives and presenting symptoms. Demographic data, mode and route of poisoning, time from exposure to presentation, clinical symptomatology, grading and routine investigations were evaluated in addition to treatment taken and outcome.

Results

During the study period, 108 children; mean age was 7.95 ± 4.11 years (range 1. 5-16 years) presented with organophosphorous poisoning. Sixty five (60%) cases were females and 43 (40%) were males. Unintentional acts (87%) were detected more than suicidal (13%) and inhalation route (63.8%) more than ingestion (36. 2%). Miosis was the most frequent clinical sign (100%) followed by respiratory distress (77.7%). Regarding time of presentation to emergency department, 43 (40%) cases were presented within 6 h while others presented more than 6 h post-exposure. Mechanical ventilation (MV) was needed for 14 (13%) cases and 6 (5.5%) cases died due to respiratory failure. Duration of hospital stay, mean time interval from toxic exposure to hospital presentation, leucocytosis, need for MV and cumulative dose of pralidoxime were significantly higher in non survivors than survivors while Pao2 (partial arterial oxygen) and GCS (Glasgow coma scale) were significantly lower.

Conclusion

This study concluded that time consumed till presentation to hospital, low GCS, need for MV, leucocytosis, decreased PaO2 and increased cumulative dose of pralidoxime were independent risk factors of mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02563-w.

Spatial patterns in prostate Cancer-specific mortality in Pennsylvania using Pennsylvania Cancer registry data, 2004-2014

BACKGROUND

Spatial heterogeneity of prostate cancer-specific mortality in Pennsylvania remains unclear. We utilized advanced geospatial survival regressions to examine spatial variation of prostate cancer-specific mortality in PA and evaluate potential effects of individual- and county-level risk factors.

METHODS

Prostate cancer cases, aged ≥40 years, were identified in the 2004-2014 Pennsylvania Cancer Registry. The 2018 County Health Rankings data and the 2014 U.S. Environmental Protection Agency's Environmental Quality Index were used to extract county-level data. The accelerated failure time models with spatial frailties for geographical correlations were used to assess prostate cancer-specific mortality rates for Pennsylvania and by the Penn State Cancer Institute (PSCI) 28-county catchment area. Secondary assessment based on estimated spatial frailties was conducted to identify potential health and environmental risk factors for mortality.

RESULTS

There were 94,274 cases included. The 5-year survival rate in PA was 82% (95% confidence interval, CI: 81.1-82.8%), with the catchment area having a lower survival rate 81% (95% CI: 79.5-82.6%) compared to the non-catchment area rate of 82.3% (95% CI: 81.4-83.2%). Black men, uninsured, more aggressive prostate cancer, rural and urban Appalachia, positive lymph nodes, and no definitive treatment were associated with lower survival. Several county-level health (i.e., poor physical activity) and environmental factors in air and land (i.e., defoliate chemical applied) were associated with higher mortality rates.

CONCLUSIONS

Spatial variations in prostate cancer-specific mortality rates exist in Pennsylvania with a higher risk in the PSCI's catchment area, in particular, rural-Appalachia. County-level health and environmental factors may contribute to spatial heterogeneity in prostate cancer-specific mortality.

Association between intake of fruits and vegetables by pesticide residue status and coronary heart disease risk

BACKGROUND

Fruit and vegetable (FV) intake is recommended for the prevention of coronary heart disease (CHD). FVs are also an important source of exposure to pesticide residues. Whether the relations of FV intake with CHD differ according to pesticide residue status is unknown.

OBJECTIVE

To examine the associations of high- and low-pesticide-residue FVs with the risk of CHD.

METHODS

We followed 145,789 women and 24,353 men free of cardiovascular disease and cancer (excluding non-melanoma skin cancer) at baseline and participating in three ongoing prospective cohorts: the Nurses' Health Study (NHS: 1998-2012), the NHS-II (1999-2013), and the Health Professionals Follow-up Study (HPFS: 1998-2012). FV intake was assessed via food frequency questionnaires. We categorized FVs as having high- or low-pesticide-residues using a validated method based on pesticide surveillance data from the US Department of Agriculture. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95%CI) of CHD in relation to high- and low-pesticide-residue FV intake.

RESULTS

A total of 3707 incident CHD events were identified during 2,241,977 person-years of follow-up. In multivariable-adjusted models, a greater intake of low-pesticide-residue FVs was associated with a lower risk of CHD whereas high-pesticide-residue FV intake was unrelated to CHD risk. Specifically, compared with individuals consuming <1 serving/day of low-pesticide-residue FVs, those consuming ≥4 servings/day had 20% (95CI: 4%, 33%) lower risk of CHD. The corresponding HR (comparing ≥4 servings/day to <1 serving/day) for high-pesticide-residue FV intake and CHD was 0.97 (95%CI: 0.72, 1.30).

CONCLUSIONS

Our data suggested exposure to pesticide residues through FV intake may modify some cardiovascular benefits of FV consumption. Further confirmation of these findings, especially using biomarkers for assessment of pesticide exposure, is needed.

Occupational Risk Factors for Prostate Cancer: A Meta-analysis

Prostate cancer is the second most common cancer in men worldwide. There are many occupational factors that have been suggested to cause prostate cancer. Our aim was to evaluate the evidence for causality by a literature review of occupational factors. We searched literature in Medline and SCOPUS from 1966 to June 30, 2015 to identify occupational risk factors for prostate cancer. The following risk factors were selected: farmers/agricultural workers, pesticides - whole group, and separately organophosphate and organochlorine pesticides, carbamates and triazines, cadmium, chromium, cutting fluids, acrylonitrile, rubber manufacturing, whole body vibration, shift work, flight personnel, ionizing radiation, and occupational physical activity. For each factor a literature search was performed and presented as meta-analysis of relative risk and heterogeneity (Q and I2 index). A total of 168 original studies met the inclusion criteria with 90,688 prostate cancer cases. Significantly increased risks were observed for the following occupational exposures: pesticides (metaRR = 1.15, 95% confidence interval [CI] = 1.01-1.32; I2 = 84%), and specifically group of organochlorine pesticides (meta relative risk [metaRR] = 1.08, 95% CI = 1.03-1.14; I2 = 0%), chromium (metaRR = 1.19, 95% CI = 1.07-1.34; I2 = 31%), shift work (metaRR = 1.25, 95% CI = 1.05-1.49; I2 = 78%) and pilots (metaRR = 1.41, 95% CI = 1.02-1.94; I2 = 63%) and occupational physical activity in cohort studies (metaRR = 0.87, 95% CI = 0.81-0.94; I2 = 0%). The literature review supports a causal association for a few of the previously suggested factors.

Non-Hodgkin lymphoma among Brazilian agricultural workers: A death certificate case-control study

To estimate the non-Hodgkin lymphoma (NHL) mortality risk among agricultural workers in Brazil's southern states, we used death certificates to identify cases of NHL between the ages of 20 and 69 years from residents of nonurban municipalities between 1996 and 2005 (n = 1,317). Controls were randomly selected from those whose underlying cause of death did not include neoplasm or hematological diseases and paired with cases by sex, age, year of death, and state of residence (n = 2,634). Odds of being an agricultural worker among cases and controls were estimated by conditional logistic regression, stratified and adjusted by sex, state, education, and race. An increased risk of death by NHL was observed among agricultural workers 20-39 years old (OR_adj = 2.06; 95% CI 95%, 1.20-3.14). Our results suggest that the young agricultural workers from southern Brazil were more likely to die of NHL compared to nonagricultural workers.

Exposure to pesticides and prostate cancer: systematic review of the literature

INTRODUCTION

Investigations about the association between prostate cancer and environmental and/or occupational pesticide exposure have evidenced a possible role of these chemical substances on tumor etiology, related to their action as endocrine disruptors.

OBJECTIVE

To assess the association between pesticide exposure and prostate cancer by conducting a systematic review of the scientific literature.

MATERIALS AND METHODS

Articles published until August 18, 2015 were searched in the databases MEDLINE/Pubmed, Scielo, and Lilacs using the keywords "pesticides" and "prostate cancer". Only the analytical observational studies whose methodological quality met the criteria established by the New Castle-Ottawa scale were included in this review.

RESULTS

The review included 49 studies published between 1993 and 2015. All studies were in English and analyzed exposure to pesticides and/or agricultural activities. Most studies (32 articles) found a positive association between prostate cancer and pesticides or agricultural occupations, with estimates ranging from 1.01 to 14.10.

CONCLUSION

The evidence provided by the reviewed studies indicates a possible association between the development of prostate cancer and pesticide exposure and/or agricultural occupations.

A Cross-Sectional Study of Pesticide Use and Knowledge of Smallholder Potato Farmers in Uganda

In response to increased pest and disease problems, potato farmers use pesticides, which could raise environmental and health concerns. This study sought to promote proper and safe pesticide-handling practices by providing data needed to guide pesticide regulation policy and training for extension staff and farmers. A household survey was conducted in three major potato-growing agroecological zones of Uganda. Two hundred and four potato farmers were interviewed about the type and source of pesticides they use in potato cultivation, the frequency of applications, the use of protective clothing, and cases of pesticide poisoning. The types of pesticides used in potato were fungicides (72%), insecticides (62%), and herbicides (3%). Overall, use of personal protective equipment was low, that is, gumboots (73%), gloves (7%), face masks (16%), and long sleeve shirts (42%). Forty-three percent of farmers who applied pesticides reported having experienced skin itching, 25% skin burning sensation, 43% coughing, 60% a runny nose, 27% teary eyes, and 42% dizziness. An IPM approach involving only moderately to slightly hazardous pesticides when pest and disease incidence has reached economic injury levels and by considering all safety measures during application and storage would be environmentally recommendable and result in reduced health risks.

Overview of the National Occupational Mortality Surveillance (NOMS) system: leukemia and acute myocardial infarction risk by industry and occupation in 30 US states 1985-1999, 2003-2004, and 2007

BACKGROUND

Cancer and chronic disease are leading causes of death in the US with an estimated cost of $46 billion.

METHODS

We analyzed 11 million cause-specific deaths of US workers age 18-64 years in 30 states during 1985-1999, 2003-2004, and 2007 by occupation, industry, race, gender, and Hispanic origin.

RESULTS

The highest significantly elevated proportionate leukemia mortality was observed in engineers, protective service, and advertising sales manager occupations and in banks/savings &loans/credit agencies, public safety, and public administration industries. The highest significantly elevated smoking-adjusted acute myocardial infarction mortality was noted in industrial and refractory machinery mechanics, farmers, mining machine operators, and agricultural worker occupations; and wholesale farm supplies, agricultural chemical, synthetic rubber, and agricultural crop industries.

CONCLUSIONS

Significantly elevated risks for acute myocardial infarction and leukemia were observed across several occupations and industries that confirm existing reports and add new information. Interested investigators can access the NOMS website at http://www.cdc.gov/niosh/topics/NOMS/.

A review of prostate cancer incidence and mortality studies of farmers and non-farmers, 2002-2013

OBJECTIVES

To review the recent literature on the incidence and mortality of prostate cancer in farmers compared to non-farmers.

METHODS

Searches were conducted in seven electronic databases for observational studies published from 2002 to 2013. Studies were assessed against eligibility criteria and a narrative summary of findings presented.

RESULTS

Eighteen primary research articles were included in the review. Four of ten mortality studies and two of nine incidence studies reported statistically significant increases in prostate cancer risk in farmers. However, nearly half of all studies reported non-significant reductions in farmers' risk. Additionally, one study reported significantly increased and decreased risk using different outcome measures. Results varied considerably by geographic region, study design and degree of control for confounders, affecting comparability and strength of findings.

CONCLUSIONS

The overall evidence for increased prostate cancer risk in farmers was weak.

Risk factors, health behaviors, and injury among adults employed in the transportation, warehousing, and utilities super sector

BACKGROUND

The TWU super sector is engaged in the movement of passengers and cargo, warehousing of goods, and the delivery of services. The purpose of this study is to describe employee self-reported personal risk factors, health behaviors and habits, disease and chronic conditions, and employer-reported nonfatal injury experiences of workers in the TWU super sector.

METHODS

National Health Interview Survey (NHIS) data for 1997-2007, grouped into six morbidity and disability categories and three age groups, were reviewed. Demographic characteristics and prevalence estimates are reported for workers in the TWU super sector and the entire U.S. workforce, and compared with national adult population data from the NHIS. Bureau of Labor Statistics employer-reported TWU injury data from 2003 to 2007 was also reviewed.

RESULTS

An average of 8.3 million workers were employed annually in the TWU super sector. TWU workers 65 or older reported the highest prevalence of hypertension (49%) across all industry sectors, but the 20% prevalence is notable among middle age workers (25-64). TWU workers had the highest prevalence of obesity (28%), compared to workers in all other industry sectors. Female TWU workers experienced the highest number of lost workdays (6.5) in the past year across all TWU demographic groups.

CONCLUSIONS

Self-reported high proportions of chronic conditions including hypertension and heart disease combined with elevated levels of being overweight and obese, and lack of physical activity-particularly among TWUs oldest workers-can meaningfully inform wellness strategies and interventions focused on this demographic group. Am. J. Ind. Med. 56:556-568, 2013. © 2012 Wiley Periodicals, Inc.

Mortality in the California Farmer Health Study cohort

Western agriculture, in comparison with Midwestern and Eastern, is more diverse, with a drier climate, mild winters, and different exposures. This randomly selected cohort of 1947 Californian farmers confirmed the usual finding: a lower mortality rate than general population (by 50%). A low smoking prevalence and healthy worker effect are likely contributors. Although farmers were more likely to die from injuries and skin cancer, death was less likely from Alzheimer's and cerebrovascular diseases. Within the cohort, disability and persistent wheeze were associated with increased mortality. The 200 deaths were insufficient to determine the significance of rare diseases.

Occupational exposures and mortality from cardiovascular disease among women textile workers in Shanghai, China

BACKGROUND

Exposure to textile fiber dusts, like particulate air pollution, may be associated with cardiovascular disease (CVD) mortality. Bacterial endotoxin, a potent inflammagen found in cotton dust, may be a specific risk factor.

METHODS

Female textile workers (N = 267,400) in Shanghai, China were followed for CVD mortality (1989-2000). Factory exposures were approximated by sector classifications based on materials and processes. Quantitative endotoxin and cotton dust measures were available for a subcohort (n = 3,188). Cox proportional hazards modeling was used to estimate hazard ratios (HR) and 95% confidence interval (CI).

RESULTS

Slightly elevated mortality risk for the cotton sector was seen for ischemic stroke (HR = 1.12, 95% CI: 0.97-1.31) and hemorrhagic stroke (HR = 1.12, 95% CI: 1.02-1.23). Similar hemorrhagic stroke mortality risk was observed in high dust sectors (HR = 1.12, 95% CI: 1.02-1.24). No association was observed for ischemic heart disease.

CONCLUSIONS

Exposures in textile factories may have contributed to CVD mortality among this cohort. The specific components of these exposures that may be harmful are not clear and should be further investigated.

Gender differences in acute pesticide-related illnesses and injuries among farmworkers in the United States, 1998-2007

BACKGROUND

Farmworkers have a high risk for acute pesticide-related illness and injury, and the rate among female farmworkers is approximately twice as high as that among males. Surveillance data were used to identify reasons for this gender difference.

METHODS

We identified acute pesticide-related illness and injury cases among farmworkers from the Sentinel Event Notification System for Occupational Risks (SENSOR)-Pesticides Program and the California Department of Pesticide Regulation. Gender-specific associations with acute pesticide-related illness and injury were assessed using chi-square tests. National Agricultural Workers Survey data were also examined.

RESULTS

The over-representation of females among farmworker illness and injury cases was confined to females who did not handle pesticides (non-handlers). Female non-handler farmworkers who were affected were more likely to be working on fruit and nut crops, to be exposed to off-target pesticide drift, and to be exposed to fungicides and fumigants compared to males.

CONCLUSIONS

Although there is an increased risk for acute pesticide-related illness and injury among female farmworkers, the absolute number of farmworkers with acute pesticide-related illness and injury is far higher among males than females. Furthermore, farmworkers have little or no control over many of the identified contributing factors that led to illness and injury. Stringent enforcement of existing regulations and enhanced regulatory efforts to protect against off-target drift exposures may have the highest impact in reducing acute pesticide-related illness and injury among farmworkers.

Mortality in the agricultural health study, 1993-2007

Comparing agricultural cohorts with the general population is challenging because the general healthiness of farmers may mask potential adverse health effects of farming. Using data from the Agricultural Health Study, a cohort of 89,656 pesticide applicators and their spouses (N = 89, 656) in North Carolina and Iowa, the authors computed standardized mortality ratios (SMRs) comparing deaths from time of the enrollment (1993-1997) through 2007 to state-specific rates. To compensate for the cohort's overall healthiness, relative SMRs were estimated by calculating the SMR for each cause relative to the SMR for all other causes. In 1,198,129 person-years of follow-up, 6,419 deaths were observed. The all-cause mortality rate was less than expected (SMR(applicators) = 0.54, 95% confidence interval (CI): 0.52, 0.55; SMR(spouses) = 0.52, 95% CI: 0.50, 0.55). SMRs for all cancers, heart disease, and diabetes were significantly below 1.0. In contrast, applicators experienced elevated numbers of machine-related deaths (SMR = 4.15, 95% CI: 3.18, 5.31), motor vehicle nontraffic accidents (SMR = 2.80, 95% CI: 1.81, 4.14), and collisions with objects (SMR = 2.12, 95% CI: 1.25, 3.34). In the relative SMR analysis for applicators, the relative mortality ratio was elevated for lymphohematopoietic cancers, melanoma, and digestive system, prostate, kidney, and brain cancers. Among spouses, relative SMRs exceeded 1.0 for lymphohematopoietic cancers and malignancies of the digestive system, brain, breast, and ovary. Unintentional fatal injuries remain an important risk for farmers; mortality ratios from several cancers were elevated relative to other causes.

Pesticide use and opportunities of exposure among farmers and their families: cross-sectional studies 1998-2006 from Hebron governorate, occupied Palestinian territory

BACKGROUND

Adverse health effects caused by pesticide exposure have been reported in occupied Palestinian territory and the world at large. The objective of this paper is to compare patterns of pesticide use in Beit-U'mmar village, West Bank, between 1998 and 2006.

METHODS

We studied two populations in Beit-U'mmar village, comprised of: 1) 61 male farmers and their wives in 1998 and 2) 250 male farmers in 2006. Both populations completed a structured interview, which included questions about socio-demographic factors, types of farming tasks, as well as compounds, quantities, and handling of pesticides. Using the 1998 population as a reference, we applied generalized linear regression models (GLM) and 95% confidence intervals (CI) in order to estimate prevalence differences (PD) between the two populations.

RESULTS

In 1998, farmers used 47 formulated pesticides on their crops. In 2006, 16 of these pesticides were still in use, including five internationally banned compounds. There were positive changes with less use of large quantities of pesticides (>40 units/year) (PD -51; CI -0.60, -0.43), in applying the recommended dosage of pesticides (PD +0.57; CI +0.48, +0.68) and complying with the safety period (PD +0.89; CI+0.83, +0.95). Changes also included farmers' habits while applying pesticides, such as less smoking (PD -0.20; CI-0.34, -0.07) and eating at the work place (PD -0.33; CI-0.47, -0.19). No significant changes were found from 1998 to 2006 regarding use of personal protective equipment, pesticide storage, farmers' habits after applying pesticides, and in using some highly hazardous pesticides.

CONCLUSIONS

The results were based on two cross-sectional surveys and should be interpreted with caution due to potential validity problems. The results of the study suggest some positive changes in the handling of pesticides amongst participants in 2006, which could be due to different policy interventions and regulations that were implemented after 1998. However, farm workers in Beit -U'mmar village are still at risk of health effects because of ongoing exposure to pesticides. To the best of our knowledge, no studies on long-term changes in pesticide use have been reported from developing countries.

Pesticide use and myocardial infarction incidence among farm women in the agricultural health study

OBJECTIVE

To evaluate the relationship between pesticide use and myocardial infarction (MI) among farm women.

BACKGROUND

Little is known about the potential association between pesticide use and cardiovascular outcomes.

METHODS

We used logistic regression to evaluate pesticide use and self-reported incident nonfatal MI among women in the Agricultural Health Study.

RESULTS

Of those MI-free at enrollment (n = 22,425), 168 reported an MI after enrollment. We saw no association with pesticide use overall. Six of 27 individual pesticides evaluated were significantly associated with nonfatal MI, including chlorpyrifos, coumaphos, carbofuran, metalaxyl, pendimethalin, and trifluralin, which all had odds ratios >1.7. These chemicals were used by <10% of the cases, and their use was correlated, making it difficult to attribute the risk elevation to a specific pesticide.

CONCLUSION

Pesticides may contribute to MI risk among farm women.

Plasma organochlorines and subsequent risk of prostate cancer in Japanese men: a nested case-control study

BACKGROUND

Although accumulating evidence suggests that exposure to organochlorine pesticides and polychlorinated biphenyls (PCBs) may contribute to the development of prostate cancer, few investigations have used biological samples to classify exposure to specific organochlorines. To our knowledge, this is the first prospective study to investigate the association between blood levels of organochlorines and prostate cancer risk.

METHODS

We conducted a nested case-control study using data from the Japan Public Health Center-based Prospective (JPHC) Study. A total of 14,203 men 40-69 years old who returned the baseline questionnaire and who provided blood samples were followed from 1990 to 2005. Using a mean follow-up period of 12.8 years, we identified 201 participants who were newly diagnosed with prostate cancer. Two matched controls for each case were selected from the cohort. We used a conditional logistic regression model to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for prostate cancer in relation to plasma levels of nine organochlorines: PCBs, dichlorodiphenyltrichloroethane (DDT), hexachlorobenzene (HCB), beta-hexachlorocyclohexane (beta-HCH), trans- and cis-nonachlor, oxychlordane, and mirex.

RESULTS

No statistically significant association with total prostate cancer was seen for any plasma organochlorine, although we did observe an insignificant inverse association for plasma HCB and beta-HCH. Total PCB in plasma was also inversely associated with advanced prostate cancer but without statistical significance.

CONCLUSION

Our results suggest that no overall association exists between prostate cancer and organochlorines at the levels measured in our study population.

Surveillance of occupational health disparities: challenges and opportunities

Increasingly, the occupational health community is turning its attention to the effects of work on previously underserved populations, and researchers have identified many examples of disparities in occupational health outcomes. However, the occupational health status of some underserved worker populations is not described due to limitations in existing surveillance systems. As such, the occupational health community has identified the need to enhance and improve occupational health surveillance to describe the nature and extent of disparities in occupational illnesses and injuries (including fatalities), identify priorities for research and intervention, and evaluate trends. This report summarizes the data sources and methods discussed at an April 2008 workshop organized by NIOSH on the topic of improving surveillance for occupational health disparities. We discuss the capability of existing occupational health surveillance systems to document occupational health disparities and to provide surveillance data on minority and other underserved communities. Use of administrative data, secondary data analysis, and the development of targeted surveillance systems for occupational health surveillance are also discussed. Identifying and reducing occupational health disparities is one of NIOSH's priority areas under the National Occupational Research Agenda (NORA).

Prevalence and changes in chronic diseases among South Korean farmers: 1998 to 2005

Background

Epidemiologic studies have suggested a unique pattern of disease among farmers in Western countries, but limited information is available about the magnitude of disease prevalence and their changes over time in Asian farmers. The aim of this study was to compare the prevalence and changes in chronic diseases among farmers with those of other occupational groups in South Korea.

Methods

Using data from three consecutive cross-sectional national surveys: the Korean National Health and Nutrition Examination Survey 1998 (n = 39,060), 2001 (n = 37,769), and 2005 (n = 34,145), we calculated age and gender-standardized prevalence of chronic diseases by the direct method and compared the prevalence changes from 1998 to 2005.

Results

Female farmers had significantly higher chronic disease prevalence than other occupational groups in all three surveys. Arthritis was the most prevalent chronic disease among farmers for both men and women. Compared with other populations, farmers demonstrated a higher prevalence of arthritis and intervertebral disc disorders. Farmers showed higher prevalence changes for intervertebral disc disorders than other occupational workers.

Conclusion

Our findings support that South Korean farmers have a distinct pattern of diseases prevalence from other populations. More detailed studies investigating the risk of musculoskeletal diseases and intensive intervention efforts to reduce the prevalence these diseases, particularly among female farmers, are required.

Occupational segregation as a determinant of US worker health

BACKGROUND

Racial segregation provides a potential mechanism to link occupations with adverse health outcomes.

METHODS

An African-American segregation index (I(AA)) was calculated for US worker groups from the nationally representative pooled 1986-1994 National Health Interview Survey (n = 451,897). Ranking and logistic regression analyses were utilized to document associations between I(AA) and poor worker health.

RESULTS

There were consistent positive associations between employment in segregated occupations and poor worker health, regardless of covariate adjustment or stratification (e.g., age, gender, income, education, or geographic region). This association between segregation and poor health was stronger for White as compared to African-American workers.

CONCLUSIONS

Occupational segregation negatively affects all workers. Potential mechanisms need to be identified through which occupational segregation may adversely impact worker health.

Ethnic, racial, and gender variations in health among farm operators in the United States

PURPOSE

The purpose of this study was to collect baseline prevalence data on the health problems faced by minority, white, and female farm operators.

METHODS

An occupational health survey of farm operators was conducted by the U.S. Department of Agriculture, National Agricultural Statistics Service between February and August 2000. A stratified random sample of farm operators from 50 U.S. states based on the 1997 Census of Agriculture was selected for telephone interview. Interviews were primarily conducted using a computer assisted telephone instrument system.

RESULTS

Population prevalences were calculated for 7137 farm operators. Prevalences were greatest for musculoskeletal discomfort, followed by respiratory problems, hearing loss, and hypertension. Generally, Latino and Asian American operators had lower prevalences for health problems than white non-Latino and white operators, respectively. African-American operators had greater prevalences for hypertension, and osteoarthritis, but lower prevalences for hearing loss, skin problems, heart problems, and cancer than white operators. American Indian or Alaska Native operators had higher prevalences for musculoskeletal problems, skin problems, and hypertension.

CONCLUSIONS

Prevalences for the different ethnicity and race groups are not the same. Studies that combine racial and ethnic groups, or study only white and non-Latino farm operators may overestimate or underestimate the prevalence of health conditions in the entire farm operator population.

Cancer mortality and farming in South Korea: an ecologic study

OBJECTIVE

The aim of this study was to examine the geographical difference of cancer mortality to determine any potential associations between cancer mortality and farming in South Korea.

METHODS

We calculated standardized mortality ratios (SMRs) based on age- and gender-specific cancer mortality rates for 245 geographic areas, using the registered death data from 2000 to 2004 that were obtained from the Korea National Statistical Office. Using the data from the Agriculture Census in 1995, we obtained the farming index. Poisson regression analysis was used to evaluate the associations between cancer mortality and farming after adjustment for socioeconomic factors.

RESULTS

The SMR analyses based on 62,403 annual average cancer deaths yielded regional variations for all cancers combined in men (SMR = 70-192) and women (SMR = 80-132). With increasing farming index we found significantly elevated cancer mortality of esophagus, stomach, brain, and leukemia for men, and of esophagus and stomach for women, whereas the SMR for colorectal and gall bladder cancers were inversely associated with farming. The results were similar when the analyses were repeated after the exclusion of metropolitan areas.

CONCLUSIONS

Our findings suggest a possible association between farming and mortality from a few cancer sites in South Korea.

Pesticide exposure, risk factors and health problems among cutflower farmers: a cross sectional study

This was a cross-sectional study which aimed to determine associations between hematologic indices such as red blood cell cholinesterase (RBC) and mean corpuscular volume (MCV), with illnesses related to pesticide exposure among cutflower farmers in La Trinidad, Benguet. One hundred two (102) randomly selected cutflower farmers underwent comprehensive, personal physical health and laboratory examinations and answered a questionnaire on work practices and illness. Majority were males (52%) and most belonged to the 20–35 age group (45%). Majority of exposed farmers were symptomatic, with most common complaints being headache (48%), easy fatigability (46.1%) and cough (40.2%). Analysis showed that RBC cholinesterase levels were positively associated with age (p = 0.02), and selling pesticide containers (p = 0.008). number of years of using pesticides (p = 0.022), use of contaminated cloth (p = 0.033), incorrect mixing of pesticides (p = 0.041), sex (p = 0.002) and illness due to pesticides (p = 0.005) were correlated with abnormal MCV. Significant associations were also found for hemoglobin, hematocrit, RBC, white blood cell (WBC) and platelet count. Predictors of RBC cholinesterase were years of pesticide use (p = 0.037) and abnormalities on health (p = 0.029). The findings of the study can be used for information dissemination and pesticide reduction programs for the cutflower farmers.

Mortality among pesticide applicators exposed to chlorpyrifos in the Agricultural Health Study

BACKGROUND

Chlorpyrifos is one of the most widely used organophosphate insecticides in the United States. Although the toxicity of chlorpyrifos has been extensively studied in animals, the epidemiologic data are limited.

OBJECTIVE

To evaluate whether agricultural chlorpyrifos exposure was associated with mortality, we examined deaths among pesticide applicators in the Agricultural Health Study, a prospective study of licensed pesticide applicators in Iowa and North Carolina.

METHODS

A total of 55,071 pesticide applicators were included in this analysis. Detailed pesticide exposure data and other information were obtained from self-administered questionnaires completed at the time of enrollment (1993-1997). Lifetime chlorpyrifos use was divided into tertiles. Poisson regression analysis was used to evaluate the exposure-response relationships between chlorpyrifos use and causes of death after adjustment for potential confounders.

RESULTS

A total of 1,851 deaths (588 among chlorpyrifos users) were observed during the study period, 1993-2001. The relative risk (RR) of death from all causes combined among applicators exposed to chlorpyrifos was slightly lower than that for nonexposed applicators (RR = 0.90; 95% confidence interval, 0.81-1.01). For most causes of death analyzed, there was no evidence of an exposure-response relationship. However, the relative risks for mortality from suicide and non-motor-vehicle accidents were increased 2-fold in the highest category of chlorpyrifos exposure days.

CONCLUSIONS

Our findings of a possible association between chlorpyrifos use and external causes of death were based on small numbers. However, the findings may reflect a link between chlorpyrifos and depression or other neurobehavioral symptoms that deserves further evaluation.

Cancer Survival in California Hispanic Farmworkers, 1988-2001

CONTEXT

Although epidemiologic studies have identified elevated cancer risk in farmworkers for some cancer types, little is known about cancer survival in this population.

PURPOSE

To determine if cancer survival differs between a Hispanic farmworker population and the general Hispanic population in California.

METHODS

Hispanic United Farm Workers of America union members and California Hispanics diagnosed from 1988 to 2001 with a first primary cancer were identified from the California Cancer Registry. Kaplan-Meier observed 5-year cause-specific survival rates were calculated, and log-rank tests assessed population differences. Cox proportional hazards models for the most common cancers provided age-, stage-, and year of diagnosis-adjusted hazard ratios.

FINDINGS

Observed 5-year cancer-specific survival rates were lower for Hispanic United Farm Workers of America men compared to California Hispanic men for all cancer sites combined (53.7% vs 57.7%, respectively) and colorectal cancer (48.1% vs 60.6%, respectively) and higher for non-Hodgkin's lymphoma (86.7% vs 57.6%, respectively). Only non-Hodgkin's lymphoma survival differences remained significant (P = .021) after adjusting for age and stage at diagnosis. No statistically significant survival differences were detected between United Farm Workers of America and California Hispanic women.

CONCLUSIONS

Although survival was generally similar between United Farm Workers of America members and California Hispanics, lower crude survival among United Farm Workers of America men for all sites combined and colorectal cancer warrants public health measures to address barriers to cancer screening in California's Hispanic farm-working populations. Histology-specific analyses with larger sample sizes are required before reaching conclusions on non-Hodgkin's lymphoma survival differences.

Proportionate mortality among current and former members of the United Farm Workers of America, AFL-CIO, in California 1973-2000

CONTEXT

To further investigate mortality among farm workers, a proportionate mortality ratio (PMR) analysis was conducted among the membership of the United Farm Workers of America (UFW), a farm worker labor union, for the years 1973-2000 in the state of California.

PURPOSE

This report compares proportionate mortality for 118 causes of death in the UFW and the general United States population, adjusting for age, sex, race and calendar year of death. In addition, an exploratory analysis was conducted comparing deaths in the UFW to deaths in the California Hispanic population.

METHODS

A roster of members of the UFW was compared to the death certificate master files of the state of California for the years 1973 to 2000. Matches were detected using automated techniques and visual review. PMR and associated confidence intervals were calculated using the National Institute for Occupational Safety and Health Life Table Analysis System using deaths in the U.S. as the standard. A similar analysis was conducted limiting attention to the time period 1988-2000 and using deaths in the California Hispanic population as the standard.

FINDINGS

There were a total of 139,662 members of the union included in the linkage that yielded 3,977 deaths in the time period 1973-2000. Proportionate mortality in the farm workers was significantly elevated for respiratory tuberculosis, malignant neoplasms of the stomach, biliary passages, liver and gallbladder, and uterine cervix, diabetes mellitus, cerebrovascular disease, cirrhosis of the liver, and "other diseases of the digestive system." Transportation injuries including motor vehicles deaths, deaths from machine injuries, unintentional poisonings and assault and homicide were significantly elevated as well. Farm workers were at significantly lower risk of death from HIV-related disease, malignant neoplasms of the esophagus, intestine, pancreas, lung, urinary bladder, melanoma, and brain, all cancer deaths, "other diseases of the nervous system," ischemic heart disease, conductive disorder, "other diseases of the heart," emphysema, "other respiratory diseases," and symptoms and ill-defined conditions. These results were similar when using California Hispanic deaths as the standard for the years 1988-2000. There was still excess proportionate mortality from tuberculosis, cerebrovascular disease and unintentional injuries among the UFW members and lowered mortality from HIV related deaths, all cancer deaths combined and diseases of the heart.

CONCLUSIONS

These results include some unique findings in regard to both excess and deficits of mortality that may be explained by the Hispanic ethnicity and recent immigration of the cohort.

Adiposity affects human response to inhaled organic dust

BACKGROUND

Swine containment facilities are often highly contaminated with organic dusts that often contain varying levels of endotoxins and other microbial products. This study was performed to evaluate the effect of obesity on the inflammatory response induced by chronic or acute exposure to swine confinement buildings (SCB).

METHODS

Two separate studies were performed; Study I included 36 SCB long-time workers and a control group of 35 matched male hospital workers never exposed to SCB. In Study II, 14 naïve healthy young subjects (8 overweight and 6 lean) volunteered to be acutely exposed to a SCB environment for 5 hr. Markers of sub-clinical inflammation linked to obesity (C-reactive protein (CRP), interleukin 6 (IL-6)) or to active inflammation (soluble adhesion molecules, IL-8, TNF) were measured.

RESULTS

In the first study, positive correlations were found between girth circumference and serum levels of IL-6 (r = 0.57, P = 0.0003) and CRP (r = 0.62, P < 0.0001) in the control group. These correlations were however blunted or lost in the SCB workers group who showed positive correlations between girth circumference and soluble l-selectin (r = 0.34, P = 0.04), TNFalpha (r = 0.37, P = 0.03), ICAM-1 (r = 0.61, P < 0.0001). In the second study involving acute SCB exposure of naïve volunteers, no significant differences were observed between normal weight and overweight subjects for white blood cells, nasal lavage cell counts, and IL-8 levels. However, higher levels of CRP, TNF, and IL-6 were detected in overweight volunteers compared to those who were lean.

CONCLUSIONS

In pig farmers (Study I), environmentally induced chronic inflammation appears to blunt the sub-clinical inflammation linked to obesity, whereas in naïve volunteers of Study II, environmentally induced acute inflammation seems to have a potentiating effect on obesity-related inflammatory markers.

Insecticide urinary metabolites in nonoccupationally exposed populations

The wide use of insecticides in agricultural and residential settings has resulted in environmental contamination, leading to increased concern about exposure of the population and possible chronic effects on health. This review summarizes the studies that have measured urinary metabolites to assess exposure of nonoccupationally exposed population to nonpersistent insecticides, organophosphates (OPs), carbamates, and pyrethroids. Electronic search yielded 36 different studies performed in a small number of countries for the last 20 years, most of them dealing with OP urinary metabolites. Dialkylphosphates, specific metabolites of OPs, and specific metabolites of pyrethroids or carbamates, have been investigated. Results indicate that a wide range of the population, adults as well as children, is exposed to OPs and to a lesser extent to pyrethroids and carbamates. Levels are one to several orders of magnitude lower than those in occupational studies. The contribution of the different sources of insecticide exposure remains uncertain. Food contamination, as well as environmental and residential contamination, appears to influence exposure, especially in the case of children. Residential use of insecticides, having pets, and living near gardens or fields have all been inconstantly related to higher urinary metabolite levels. Occupational exposure of the parents, especially of the agricultural workers, seems to be a predictive factor of higher exposure of their children. More studies investigating every source and pathway of exposure of randomized population samples and in other countries than the United States, in particular in developing countries, could improve our knowledge of factors influencing insecticide exposure of the population.

Pesticides and the induction of aneuploidy in human sperm

Pesticides are some of the most frequently released toxic chemicals into the environment. Exposure to them has been associated with reproductive dysfunction, but the knowledge of the genotoxic risks of these substances is still limited. In vitro and in vivo, many pesticides are shown to induce aneuploidy. Analysis of sperm chromosomes by fluorescence in situ hybridization (FISH) with chromosome-specific probes has obtained increasing popularity in genetic toxicology. Sperm-FISH studies on men exposed to pesticides have yielded conflicting results: in men exposed to multiple pesticides during spraying no increased disomy frequencies in sperm were observed, although one study reported an increased rate of sex chromosome nullisomy. In contrast the two studies conducted in pesticide factories showed increased frequencies of sperm aneuploidy in exposed men compared to controls. The available data indicates that at least some of the commonly used pesticides are capable of inducing aneuploidy in human sperm when the exposure level is high enough.

Residential proximity to agricultural pesticide use and incidence of breast cancer in California, 1988-1997

California is the largest agricultural state in the United States and home to some of the world's highest breast cancer rates. The objective of our study was to evaluate whether California breast cancer rates were elevated in areas with recent high agricultural pesticide use. We identified population-based invasive breast cancer cases from the California Cancer Registry for 1988-1997. We used California's pesticide use reporting data to select pesticides for analysis based on use volume, carcinogenic potential, and exposure potential. Using 1990 and 2000 U.S. Census data, we derived age- and race-specific population counts for the time period of interest. We used a geographic information system to aggregate cases, population counts, and pesticide use data for all block groups in the state. To evaluate whether breast cancer rates were related to recent agricultural pesticide use, we computed rate ratios and 95% confidence intervals using Poisson regression models, adjusting for age, race/ethnicity, and neighborhood socioeconomic status and urbanization. This ecologic (aggregative) analysis included 176,302 invasive breast cancer cases and 70,968,598 person-years of observation. The rate ratios did not significantly differ from 1 for any of the selected pesticide categories or individual agents. The results from this study provide no evidence that California women living in areas of recent, high agricultural pesticide use experience higher rates of breast cancer.

Cancer incidence patterns among adolescents and young adults in the United States

OBJECTIVE

The purpose of this study was to examine age-specific cancer incidence patterns among adolescents and young adults (ages 15--49).

METHOD

Cancer incidence data for 1995--1999 from 22 population-based central cancer registries, covering about 47% of the US population, were used. Relative frequencies and average annual age-specific incidence rates per 100,000 person-year were computed for the five-year age groups from age 15--19 years through 45--49 years. Tests of significance for comparison were at a level of p<0.05.

RESULTS

The age at crossover from a predominance of non-epithelial cancers to a predominance of epithelial cancers during adolescence and young adulthood varied by gender and race. Epithelial cancer became the predominant type of tumor after age 40 years among males while it was the predominant type after age 25 years among females. There was also a shift in the top five cancer types with increasing age, which varied by race and gender. Epithelial cancers of the thyroid, breast, ovary, and cervix uteri started to increase sharply among young women in their 20s while among males epithelial cancers rarely occurred until the early 30s (ages 30--34). Cancers of the female breast, colon and rectum, and lung began to occur at an earlier age and increased more sharply among blacks than among whites. However, the incidence rates of epithelial thyroid and ovarian cancers rose more quickly among whites than blacks. Non-Hodgkin lymphoma and soft tissue sarcoma (excluded Kaposi's sarcoma) increased with age among both whites and blacks but the rates were significantly higher among blacks than among whites. Both Kaposi's sarcoma and testicular cancer incidence increased with age and peaked in the early 30s (ages 30--34). The former was significantly higher among blacks than whites while the latter was significantly higher among whites than blacks. Cervical cancer incidence leveled off when white women reached their 30s, but for black women the rate continued to rise with advancing age. Cutaneous melanoma rates were significantly higher among females than among males between the ages of 15 and 39. Conclusion Cancer incidence patterns among adolescents and young adults are distinctive. Specific cancer prevention and control strategies should be targeted accordingly and tailored to their specific needs.

Mortality among Participants in the Agricultural Health Study

PURPOSE

This analysis of the Agricultural Health Study cohort assesses the mortality experience of licensed pesticide applicators and their spouses.

METHODS

This report is based on 52,393 private applicators (who are mostly farmers) and 32,345 spouses of farmers in Iowa and North Carolina. At enrollment, each pesticide applicator completed a 21-page enrollment questionnaire. Mortality assessment from enrollment (1994-1997) through 2000 provided an average follow-up of about 5.3 years, 447,154 person-years, and 2055 deaths.

RESULTS

Compared with the general population in the two states, the cohort experienced a very low mortality rate. Standardized mortality ratios (SMRs) for total mortality, cardiovascular disease, diabetes, COPD, total cancer, and cancers of the esophagus, stomach, and lung were 0.6 or lower for both farmers and spouses. These deficits varied little by farm size, type of crops or livestock on the farm, years of handling pesticides, holding a non-farm job, or length of follow up. SMRs among ever smokers were not as low as among never smokers, but were still less than 1.0 for all smoking-related causes of death. No statistically significant excesses occurred, but slightly elevated SMRs, or those near 1.0, were noted for diseases that have been associated with farming in previous studies.

CONCLUSIONS

Several factors may contribute to the low mortality observed in this population, including the healthy worker effect typically seen in cohorts of working populations (which may decline in future years), a short follow-up interval, and a healthier lifestyle manifested through lower cigarette use and an occupation that has traditionally required high levels of physical activity.

Prostate cancer among pesticide applicators: a meta-analysis

OBJECTIVES

To analyse data from peer-reviewed, case-referent and cohort studies, studying the occurrence of prostate cancer in pesticide applicators and in some other, related, occupational categories, in order to determine a possible relationship of cancer of the prostate with pesticide exposure; to calculate a meta-rate ratio and to compare it with the meta-rate ratios obtained in a previous meta-analysis performed over a shorter time (1995-2001) in a broader exposure category, including many pesticide-related agricultural and non-agricultural occupations.

METHODS

Medline was searched for the years between 1966 and 2003, and relevant studies were identified from 1986 on. We conducted a meta-analysis of 22 studies complying with the inclusion criteria in order to pool their relative risk (RR) estimates. Studies were summarised and assessed for homogeneity and publication bias.

RESULTS

The meta-rate ratio, based on 22 estimates of RR, is 1.24 [95% confidence interval (95% CI) 1.06-1.45]. This pooled risk estimate for the occupational categories selected is higher than the one previously calculated for farmers in general over a shorter period of publication. Substantial heterogeneity of rate ratios exists between the different studies. The major source of heterogeneity identified is geographic location. Increased meta-rate ratios are observed for studies derived from North America as well as from Europe, the meta-rate ratios from Europe being lower than those from North America. There is no obvious indication of publication bias.

CONCLUSION

The increased meta-rate ratio for prostate cancer in agricultural pesticide applications provides additional evidence for a possible relationship between pesticide exposure and prostate cancer. The homogeneity observed between the individual rate ratios, after we had regrouped the data according to geographic location, tends to increase the consistency of the association. However, the data available from the individual studies do not provide sufficient exposure information for firm conclusions to be drawn about pesticide exposure as the cause of prostate cancer, independently from other factors.

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.

Issues of Agricultural Safety and Health

Agricultural work is the most prevalent type of employment in the world. In the United States only a few are engaged in creating food and fiber for many. Agriculture includes farming, ranching, fishing, and forestry, and together they carry significant risk for the development of injury or illness. There are numerous special-population issues related to agriculture. Farmers are old and growing older, many workers are children, and migrant and seasonal help, often foreign born, make up a large percentage of the workforce. It has been only relatively recently that concerns of agricultural safety and health have become a major research focus in the United States.

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.