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Background Epidemic levels of CKD of undetermined cause, termed Mesoamerican nephropathy in Central America, have been found in low- and middle-income countries. We investigated the natural history of, and factors associated with, loss of kidney function in a population at high risk for this disease. Methods We conducted a 2-year prospective, longitudinal study with follow-up every 6 months in nine rural communities in northwestern Nicaragua and included all men ( n =263) and a random sample of women ( n =87) ages 18-30 years old without self-reported CKD, diabetes, or hypertension. We used growth mixture modeling to identify subgroups of eGFR trajectory and weighted multinomial logistic regression to examine associations with proposed risk factors. Results Among men, we identified three subpopulations of eGFR trajectory (mean baseline eGFR; mean eGFR change over follow-up): 81% remained stable (116 ml/min per 1.73 m 2 ; -0.6 ml/min per 1.73 m 2 per year), 9.5% experienced rapid decline despite normal baseline function (112 ml/min per 1.73 m 2 ; -18.2 ml/min per 1.73 m 2 per year), and 9.5% had baseline dysfunction (58 ml/min per 1.73 m 2 ; -3.8 ml/min per 1.73 m 2 per year). Among women: 96.6% remained stable (121 ml/min per 1.73 m 2 ; -0.6 ml/min per 1.73 m 2 per year), and 3.4% experienced rapid decline (132 ml/min per 1.73 m 2 ; -14.6 ml/min per 1.73 m 2 per year; n =3 women). Among men, outdoor and agricultural work and lack of shade availability during work breaks, reported at baseline, were associated with rapid decline. Conclusions Although Mesoamerican nephropathy is associated with agricultural work, other factors may also contribute to this disease., (Copyright © 2018 by the American Society of Nephrology.)

Background: Occupational heat stress is a major concern in sugarcane production and has been hypothesized as a causal factor of a chronic kidney disease epidemic in Central America. This study described working conditions of sugarcane harvesters in Costa Rica and quantified their exposure to heat., Methods: Non-participatory observation and Wet Bulb Globe Temperatures (WBGT) according to Spanish NTP (Technical Prevention Notes) guidelines were utilized to quantify the risk of heat stress. OSHA recommendations were used to identify corresponding exposure limit values., Results: Sugarcane harvesters carried out labor-intensive work with a metabolic load of 261 W/m² (6.8 kcal/min), corresponding to a limit value of 26° WBGT which was reached by 7:30 am on most days. After 9:15 am, OSHA recommendations would require that workers only work 25% of each hour to avoid health risks from heat., Conclusions: Sugarcane harvesters are at risk for heat stress for the majority of the work shift. Immediate action is warranted to reduce such exposures., (Copyright © 2013 Wiley Periodicals, Inc.)

Background: The US Environmental Protection Agency voluntary phased-out residential use of chlorpyrifos in 2001. In contrast, in Costa Rica, chlorpyrifos-treated bags are increasingly used to protect banana and plantain fruits from insects and to fulfill product standards, even in populated areas., Objectives: To evaluate children's exposure to chlorpyrifos in villages situated nearby banana plantations and plantain farms in Costa Rica., Methods: The study targeted two villages with use of chlorpyrifos-treated bags in nearby banana plantations and plantain farms and one village with mainly organic production. For 140 children from these villages, mostly indigenous Ngäbe and Bribri, parent-interviews and urine samples (n=207) were obtained. Urinary 3,5,6-trichloro-2-pyridinol (TCPy) levels were measured as a biomarker for chlorpyrifos exposure. In the banana and plantain village also environmental contamination to chlorpyrifos was explored., Results: Children from the banana and plantain villages had statistically significant higher urinary TCPy concentrations than children from the referent village; 2.6 and 2.2 versus 1.3μg/g creatinine, respectively. Chlorpyrifos was detected in 30% of the environmental samples as well as in 92% of the hand/foot wash samples. For more than half of the children their estimated intake exceeded the US EPA chronic population adjusted dose. For some, the acute population adjusted dose and the chronic reference dose were also exceeded., Conclusions: Our results suggest that children living nearby plantations with chlorpyrifos-treated bags are exposed to chlorpyrifos levels that may affect their health. Interventions to reduce chlorpyrifos exposure are likely to improve children's health and environment in banana and plantain growing regions., (Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.)

Background: An epidemic of chronic kidney disease of unknown cause has emerged along the Pacific coast of Central America, particularly in relatively young male sugarcane workers. In El Salvador, we examined residence and occupations at different altitudes as surrogate risk factors for heat stress., Study Design: Cross-sectional population-based survey., Setting & Participants: Populations aged 20-60 years of 5 communities in El Salvador, 256 men and 408 women (participation, 73%): 2 coastal communities with current sugarcane and past cotton production and 3 communities above 500 m with sugarcane, coffee, and service-oriented economies., Predictor: Participant sex, age, residence, occupation, agricultural history by crop and altitude, and traditional risk factors for CKD., Outcomes: Serum creatinine (SCr) level greater than the normal laboratory range for sex, estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2, and proteinuria categorized as low (protein excretion ≥ 30-< 300 mg/dL) and high grade (≥ 300 mg/dL)., Results: Of the men in the coastal communities, 30% had elevated SCr levels and 18% had eGFR < 60 mL/min/1.73 m2 compared with 4% and 1%, respectively, in the communities above 500 m. For agricultural workers, prevalences of elevated SCr levels and eGFR < 60 mL/min/1.73 m2 were highest for coastal sugarcane and cotton plantation workers, but were not increased in sugarcane workers at 500 m or subsistence farmers. Women followed a weaker but similar pattern. Proteinuria was infrequent, of low grade, and not different among communities, occupations, or sexes. The adjusted ORs of decreased kidney function for 10-year increments of coastal sugarcane or cotton plantation work were 3.1 (95% CI, 2.0-5.0) in men and 2.3 (95% CI, 1.4-3.7) in women., Limitations: The cross-sectional nature of the study limits etiologic interpretations., Conclusion: Agricultural work on lowland sugarcane and cotton plantations was associated with decreased kidney function in men and women, possibly related to strenuous work in hot environments with repeated volume depletion., (Copyright © 2012 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Objective: This study assessed pesticide exposure of children in rural Nicaragua in relation to parental pesticide use, from around conception to current school age, as part of an epidemiological evaluation of neurodevelopment effects., Methods: We included 132 children whose parents were subsistence farmers or plantation workers, or had an agricultural history. As proxies for children's long-term exposures, we constructed cumulative parental pesticide-specific use indices for periods before and after the child's birth from data obtained using an icon-calendar-based questionnaire, of application hours (h) for plantation workers and subsistence farmers, and of kilograms of active ingredients (ai) only for subsistence farmers. Pesticide residues of TCPY, 3-PBA and 2,4-D were analysed in children's urine as indicators for current exposures., Results: Life-time indices were highest for the organophosphates chlorpyrifos (median 114 h (min 2; max 1584), 19.2 kg ai (min 0.37; max 548)) and methamidophos (84 h (6; 1964), 12.2 kg ai (0.30; 780)). The P50 values of children's urinary residues were 3.7 μg/g creatinine for TCPY, 2.8 for 3-PBA and 0.9 for 2,4-D; TCPY values are comparable with those in other countries, but 3-PBA and 2,4-D are considerably higher. The maximum levels for all three pesticides are the highest reported for children. Residues increased on days after application, but most high residue levels were unrelated to parental pesticide applications., Conclusion: Urinary pesticide residues reveal high environmental exposure among children in rural Nicaragua. The quantitative parental pesticide use indices as proxies for children's exposures during different periods may be useful for the evaluation of developmental health effects.

The Talamanca County in Costa Rica has large-scale banana and small-scale plantain production, probably causing pesticide exposure in indigenous children. We explored to what extent different community actors are aware of children's pesticide hazards and how their awareness related to socio-economical and cultural conditions. Methods comprised eight focus groups with fathers and mothers separately, 27 semi-structured interviews to key actors, and field observations. As a whole, the indigenous plantain farmers and banana plantation workers had some general knowledge of pesticides concerning crop protection, but little on acute health effects, and hardly any on exposure routes and pathways, and chronic effects. People expressed vague ideas about pesticide risks. Inter-community differences were related to pesticide technologies used in banana and plantain production, employment status on a multinational plantation versus smallholder status, and gender. Compared to formalized practices on transnational company plantations, where workers reported to feel protected, pesticide handling by plantain smallholders was not perceived as hazardous and therefore no safety precautions were applied. Large-scale monoculture was perceived as one of the most important problems leading to pesticide risks in Talamanca on banana plantations, and also on neighboring small plantain farms extending into large areas. Plantain farmers have adopted use of highly toxic pesticides following banana production, but in conditions of extreme poverty. Aerial spraying in banana plantations was considered by most social actors a major determinant of exposure for the population living nearby these plantations, including vulnerable children. We observed violations of legally established aerial spraying distances. Economic considerations were most mentioned as the underlying reason for the pesticide use: economic needs to obtain the production quantity and quality, and pressure to use pesticides by other economic agents such as middlemen. Risk perceptions were modulated by factors such as people's tasks and positions in the production process, gender, and people's possibilities to define their own social conditions (more fatalistic perceptions among banana workers). The challenge for the future is to combine these insights into improved health risk assessment and management that is culturally adequate for each particular community and agricultural context., (Copyright © 2011 Elsevier Inc. All rights reserved.)

A new method for assessment of dermal exposure to pesticides in subsistence farmers by use of determinants of dermal exposure is described. The method, called the determinants of dermal exposure ranking method (DERM), is a combination of checklists and expert rating assessment. Thus, determinants are listed in a form, which is used to check their presence and to assess them using a simple algorithm based on two factors, the type of transport process (T value) and the area of body surface exposed (A value). In addition, the type of clothing worn during applications is included as a protection factor. We applied the DERM to real pesticide applications, characterizing dermal exposure and comparing DERM estimates with earlier developed semiquantitative visual scores based on fluorescent tracer, the total visual score (TVS) and contaminated body area (CBA). DERM showed a very good level of agreement with both the TVS (r = 0.69; P = 0.000) and the CBA (r = 0.67; P = 0.000). DERM allowed identification of the determinants that had the highest effect on exposure and the farmers with the highest exposure. In conclusion, DERM provided information on the determinants responsible for dermal exposure in a group of subsistence farmers. This can be useful to design monitoring and preventive programs, define priorities for intervention and prioritize and select most adequate measurement strategies. DERM promises to be a low-cost easy-to-use method to assess dermal exposure to pesticides in developing country conditions.

We describe a model for the retrospective assessment of parental exposure to 26 pesticides, selected by toxicity-based prioritization, in a population-based case-control study of childhood leukaemia in Costa Rica (301 cases, 582 controls). The model was applied to a subset of 227 parents who had been employed or self-employed in agriculture or livestock breeding. It combines external data on pesticide use for 14 crops, 21 calendar years and 14 regions, and individual interview data on determinants (task and technology, personal protective equipment, field reentry, storing of pesticides, personal hygiene) of exposure. Recall was enhanced by use of checklists of pesticides in the interview. An external database provided information on the application rate (proxy for intensity of potential exposure) for each pesticide. The calendar time was individually converted to five time windows (year before conception, first, second and third trimester, and first year of the child). Time-windowed individual data on determinants of exposure and their expert-based general weights and their category-specific hazard values jointly provided an individual determinant score. This score was multiplied by the application rate to obtain an individual index of exposure intensity during application. Finally, average exposure intensity during entire time windows was estimated by incorporating in the model the individual time fraction of exposure during application. Estimates of exposure intensities were proxies assumed to be proportional to dermal exposure intensity, which represents the major pathway of occupational exposure to pesticides. A simulated sensitivity analysis resulted in a correlation coefficient of 0.91 between two sets of 10 000 values of individual exposure indices, based on two different but realistic sets expert-assigned weights. Lack of measurement data on concurrent exposures in comparable circumstances precluded direct validation of the model.

Objectives: Identification of pesticide exposure determinants has become an issue in explaining exposure variability and improving control measures. Most studies have been conducted in industrialized countries. The aim of this study was to identify relevant dermal exposure determinants among Nicaraguan subsistence farmers., Methods: Field data on possible determinants were collected during 32 pesticide applications through observation and supplementary videorecording. A multistep reduction strategy brought down the 110 potential exposure determinants to 27 variables, which were grouped as worksite, spray equipment, working practices, clothing or hygiene practices related. Dermal exposure was quantified with a modification of Fenske's visual scoring method. Multivariate linear regression modeling within groups and across groups was performed., Results: In the within-group analyses, work practices, spray equipment and worksite related determinants explained 52, 33 and 25% of the exposure variability, respectively. Clothing and hygiene practices were weaker determinants and did not always reduce the exposure. The final model included determinants from all groups except hygiene practices and explained 69% of the exposure variability. A less restricted model increased the explained variability to 75%. Several novel determinants were identified, including spraying on a muddy terrain, dew on plants, sealing the tank lid with a cloth and wiping sweat from the face., Conclusions: This study showed that a combination of observation and visual scoring techniques can provide valuable information on determinants of pesticide exposure and affected body parts under developing country conditions. The results could be used to develop job-specific questionnaires and to design training and preventive programs.

Pesticide exposures of women in developing countries are aggravated by economic policy changes associated with structural adjustment programs and globalization. Women in these countries, particularly in the agricultural sector, are increasingly exposed. Since they are concentrated in the most marginal positions in the formal and informal workforces, and production is organized in a gender-specific way, opportunities for women to control their exposures are limited. Data from developing countries show that: 1) women's exposures to pesticides are significantly higher than is recognized; 2) poisonings and other pesticide-related injuries are greatly underestimated for women; 3) for a given adverse outcome from exposure, the experience of that outcome is gender-discriminatory; 4) erroneous risk perception increases women's exposures. The hiatus in knowledge of gender-specific exposures and effects is related to gender biases in the nature of epidemiologic inquiry and in the literature, and the gendered nature of health workers' practices and surveillance. Recommendations are made for strong, independent organizations that provide opportunities for women to control their environments, and the factors affecting their health, as well as gender-sensitive research to address the particularities of women's pesticide exposures.

To evaluate time trends of occupational pesticide-related injuries in Costa Rica, a survey was carried out three times over a ten-year period at a national reporting system for occupational accidents and diseases among wage-earning workers. The sample comprised the accidents reported during the months of June of the years 1982, 1987, and 1992. The overall incidence rates were 1.8, 2.7, and 2.5 per 1,000 agricultural workers, respectively. Rates among female workers increased (3.1, 3.7, 5.4) and were elevated as compared with male workers (1.7, 2.6, 2.3). The trend for topical lesions was upgoing (1.2, 1.4, 2.1), consistent with an increased use of fungicides and lack of safety measures for pesticides with low acute toxicity. Systemic poisonings peaked in 1987 (0.6, 1.2, 0.5), declining in 1992 with increased use of biologic pest control and pyrethroid insecticides less toxic than cholinesterase inhibitors, and improved safety during nematocide applications on banana plantations. In 1992, despite the largest decline of systemic poisonings in the banana-producing Atlantic Region, poisonings as well as topical injuries were still four times more frequent in this region than in the rest of the country. Restriction of highly toxic pesticides together with implementation of occupational safety measures can reduce systemic poisonings in developing countries. Such policies need to be extended to other pesticides to prevent less life threatening but often disabling skin and eye injuries.

Large worker populations in the Third World are exposed to increasing amounts of pesticides, including pesticides severely restricted and banned in industrialized countries. Studies on knowledge, attitudes, and practices indicate that unsafe use of pesticides is the rule in Third World countries. Surveys of acute poisonings show high rates in these countries, despite underregistration. The scarce studies on chronic health outcomes demonstrate neurotoxic, reproductive, and dermatologic effects. Exposure assessment consists mainly of cholinesterase testing, and few studies have quantified dermal and respiratory exposure. The few intervention studies demonstrate the need for evaluation of the impact of preventive measures and policies. There is no evidence that widespread "safe-use" programs have greatly affected exposure and morbidity. It was concluded that research should focus on simple methods for surveillance of exposure and on surveillance of acute illness and its causes in order to develop and evaluate rapid local interventions. Studies on chronic effects should be carried out in selected countries, aiming at long-term and broader interventions. Policies that promote the use of pesticides should be critically evaluated. North-South and South-South research collaborations must be encouraged to address this global health problem.

Wesseling C (Pesticide Program, Universidad Nacional, Heredia, Costa Rica), Ahlbom A, Antich D, Rodriguez A C and Castro R. Cancer in banana plantation workers in Costa Rica. International Journal of Epidemiology 1996; 25: 1125–1132.Background Costa Rica has population and disease registries with potential value for epidemiological research. Pesticides have been intensively used on banana plantations, for example dibromochloropropane (DBCP). This study was planned to examine the quality of the cancer and civil registries and the feasibility of record linkages, and to explore cancer pattems among a highly exposed group. Methods A retrospective cohort study was carried out. Workers on the payrolls of banana companies, as reported to the Social Security System at any time between 1972 and 1979, were followed up in the cancer registry between 1981 and 1992: 29 565 men and 4892 women for 407 468 person-years. The observed cases of cancer were compared to the expected values, derived from the national incidence rates. Results We identified 368 cancer cases, 292 among men (standardized incidence ratio [SIR] = 76, 95% confidence interval [Cl] 67–84) and 76 among women (SIR = 116, 95% Cl : 90–142). Among men increased SIR were observed for melanoma (SIR = 197, 95% Cl: 94–362) and penile cancer (SIR = 149, 95% Cl : 55–324); among women for cervix cancer (SIR = 182, 95% Cl: 122–241) and leukaemia (SIR = 274, 95% Cl: 86–639). Risk estimates for lung cancer were elevated among male workers with the longest time of employment. Conclusions Follow-up was difficult due to deficient identification variables in the cancer registry and to easier identification of the living compared to the deceased in the civil registry at the end of the observation period. The various systematic errors in this study are likely to produce an underestimation of the relative risk estimates. This study contributes to improvements of the registries and increases the potential for cancer epidemiology in Costa Rica and other developing countries. [ABSTRACT FROM PUBLISHER]