Lower tier toxicity risk assessment of agriculture pesticides detected on the Río Madre de Dios watershed, Costa Rica.

Costa Rica is a tropical country with one of the highest biodiversity on Earth. It also has an intensive agriculture, and pesticide runoff from banana and pineapple plantations may cause a high toxicity risk to non-target species in rivers downstream the plantations. We performed a first tier risk assessment of the maximum measured concentrations of 32 pesticides detected over 4 years in the River Madre de Dios (RMD) and its coastal lagoon on the Caribbean coast of Costa Rica. Species sensitivity distributions (SSDs) were plotted in order to derive HC5 values for each pesticide, i.e., hazard concentrations for 5 % of the species, often used as environmental criteria values in other countries. We also carried out toxicity tests for selected pesticides with native Costa Rican species in order to calculate risk coefficients according to national guidelines in Costa Rica. The concentrations of herbicides diuron and ametryn and insecticides carbofuran, diazinon, and ethoprophos exceeded either the HC5 value or the lower limit of its 90 % confidence interval suggesting toxic risks above accepted levels. Risk coefficients of diuron and carbofuran derived using local guidelines indicate toxicity risks as well. The assessed fungicides did not present acute toxic risks according to our analysis. Overall, these results show a possible toxicity of detected pesticides to aquatic organisms and provide a comparison of Costa Rican national guidelines with more refined methods for risk assessment based on SSDs. Further higher tier risk assessments of pesticides in this watershed are also necessary in order to consider pesticide water concentrations over time, toxicity from pesticide mixtures, and eventual effects on ecosystem functions.

Use of cholinesterase activity as a biomarker of pesticide exposure used on Costa Rican banana plantations in the native tropical fish Astyanax aeneus (Günther, 1860).

In Costa Rica, thousands of tones of agricultural pesticides have been used for decades and their use is continuously increasing due to intensive and expanding production of coffee, pineapple, rice, ornamental plants and bananas. The objective of this study was to evaluate whether choline esterase (ChE) activity could be used as a biomarker of exposure to pesticides in the Costa Rican native fish Astyanax aeneus (characidae). Three methods used in order to evaluate the ChE biomarker were as follows: Laboratory studies where A. aeneus was exposed to organophosphate pesticide (ethoprophos); In situ 48 hr exposure assessment using caging experiments with fish exposed upstream and downstream of banana plantations and ChE activity estimation of in fish captured directly at sites with different degrees of pesticide exposure. Results from the laboratory studies showed that ChE activity in both brain and muscle tissue was significantly lower in fish exposed to ethoprophos than in controls. Fish from the caging experiments showed no difference in ChE activity neither in brain nor in muscle tissue between the four tested sites and was attributed to the short duration of the exposure. Asignificant difference in ChE activity was determined in muscle of fish captured from Laguna Madre de Dios compared to fish from Canal Batán. Although our laboratory results revealed that ChE activity in A. aeneus was highly responsive to ethoprophos, results from field experiments were less conclusive and showed that the captured fish showed large variability in ChE activity and that more research is needed before ChE activity can be used as reliable biomarker of pesticide exposure.

Neutral polyfluoroalkyl substances in the global atmosphere.

Concentrations of neutral per- and polyfluoroalkyl substances (nPFAS) in the atmosphere are of interest because nPFAS are highly mobile percursors for perfluoroalkyl acids. Two calibration studies in Ontario, Canada and Costa Rica established the feasibility of using XAD 2-resin based passive air samplers (XAD-PAS) to reliably determine long term average air concentrations of nPFAS under temperate and tropical climatic conditions. The temporal and spatial distribution of nPFAS was investigated by analyzing XAD-PAS deployed for one year at between 17 and 46 sites on six continents between 2006 and 2011 as part of the Global Atmospheric Passive Sampling (GAPS) study. Higher levels of fluorotelomer alcohols (FTOHs) compared to fluorinated sulfonamides (FOSAs), and fluorinated sulfonamidoethanols (FOSEs) were observed at all sites. Urban sites had the highest levels of nPFAS compared to rural and remote sites, which is also apparent in a positive correlation of nPFAS levels with the proximity of a sampling site to areas of high population density. Levels of FOSAs and FOSEs tended to decrease during the six years of measurements, whereas an initial decline in the concentrations of FTOHs from 2006 to 2008 did not continue in 2009 to 2011. A comparison of nPFAS levels measured in national XAD-PAS networks in Costa Rica and Botswana revealed that the GAPS sites in Tapanti and the Kalahari are representative of the more remote regions in those countries. XAD-PAS derived absolute nPFAS levels at GAPS sites are lower than those measured using another PAS, but are within the range of levels measured with active air samplers. Agreement of relative nPFAS composition is better between samplers, suggesting that the discrepancy is due to uncertain sampling rates.

Environmental hazards of pesticides from pineapple crop production in the Río Jiménez watershed (Caribbean Coast, Costa Rica).

This study aimed to characterize environmental hazards of pesticides from pineapple production in riparian communities along the Jiménez River watershed. To achieve our objectives riparian ecological quality indices on riparian habitat and macroinvertebrate assemblages were combined with toxicity assays, fish biomarkers, physico-chemical water analysis and pesticide environmental hazards. During two consecutive years and two periods (July and October), three reference and four impacted sites were monitored. The ecological quality of benthic macroinvertebrates and of riparian habitats deteriorated from the reference sites downstream to the polluted reaches along the Jiménez River area affected by pineapple plantations. The toxicity of water to Daphnia magna also increased towards downstream reaches. Biomarkers of fish of the species Poecilia gillii and Bryconamericus scleroparius transplanted across the studied sites evidenced a clear anticholinergic effect towards downstream sites as well as increased levels of lipid peroxidation. Different pesticide residues were frequently detected in water samples collected across the Jiménez River watershed with herbicides (ametryn, bromacil, diuron), organophosphorus insecticides (diazinon and ethoprophos) and triazole fungicides being the greatest reaching levels above 1 µg L(-1) in downstream sites. Principal component and environmental hazard analysis of physico-chemical and biological responses established clear relationships among habitat deterioration and the ecological quality of macroinvertebrate communities, high levels of herbicides and poor plant growth, high levels of organophosphorus insecticides in water and anticholinesterase effects on fish, D. magna mortality and deterioration of macroinvertebrate communities. Fungicide and herbicide residue levels were also related with high levels of lipid peroxidation and high activities of glutathione S transferase in fish liver, respectively. These results indicated, thus, that riparian habitat deterioration due to deforestation and land use for agriculture and pesticide contamination are affecting river ecosystems.

TICAREX: Exposiciones laborales a agentes cancerígenos y plaguicidas en Costa Rica / TICAREX: occupational exposure to carcinogens and pesticides in Costa Rica

El sistema europeo de datos CAREX (CARcinogen Exposure) considera la fuerza laboral de un país agrupada en 55 sectores económicos según la Clasificación Internacional de Actividades Económicas de las Naciones Unidas, segunda revisión de 1968, y mediante la aplicación de proporciones de trabajadores expuestos a partir de datos generados en estudios de higiene industrial para 139 agentes carcinógenos, los convierte en fuerza laboral expuesta y número de trabajadores expuestos a agentes carcinogénicos, según rama de actividad. En este artículo se describe una modificación y extensión del sistema CAREX para calcular los números de trabajadores expuestos a agentes cancerígenos y plaguicidas en Costa Rica. Esta primera aplicación de CAREX fuera de Europa (TICAREX) fue realizada en Costa Rica, Centroamérica, para 27 agentes cancerígenos y 7 grupos de plaguicidas, considerados de interés para el país, realizando estimaciones por separado para mujeres y hombres. Los agentes cancerígenos más frecuentes a los que se expone la fuerza laboral de Costa Rica de 1.3 millones fueron la radiación solar (333,000 trabajadores), las emisiones de diesel (278,000), paraquat y diquat (175,000), el humo de tabaco ambiental (71,000), los compuestos de cromo hexavalente (55,000), el benceno (52,000), mancozeb, maneb y zineb (49,000), clorotalonil (38,000), el polvo de madera (32,000), el cuarzo (27,000), benomil (19,000), el plomo y sus compuestos inorgánicos (19,000), tetracloroetileno (18,000), y los compuestos aromáticos policíclicos (17,000). En los hombres, la distribución se mantuvo muy ajustada a los anteriores rangos, sin embargo en las mujeres, debido a su diferente distribución en los sectores, el formaldehído, el radón y el cloruro de metileno superaron a los plaguicidas, el cromo (VI), el polvo de madera y el cuarzo. La agricultura, la construcción, los servicios personales y domésticos, el transporte terrestre y acuático y los servicios asociados al transporte, la fabricación de productos cerámicos y similares, la manufactura de productos de madera, la minería, la silvicultura, la pesca, la fabricación de maquinaria y aparatos eléctricos, bares y restaurantes fueron sectores de donde las exposiciones son frecuentes. Una reducción drástica de exposiciones laborales y ambientales a estos agentes daría por resultado mejoras sustanciales en los niveles de salud pública y ocupacional. La vigilancia de las exposiciones laborales y de la salud en el trabajo son esenciales para el control de la contaminación y de las exposiciones a los agentes cancerígenos

The European data system CAREX takes the workforce of a country grouped into 55 economic sectors according to the International Economic Activity Classification of the United Nations, the second 1968 revision and through the application of proportions of workers exposed to 139 carcinogenic agents based on data from industrial hygiene studies, converting it into the total workforce exposed to carcinogens by sector. . In this article we describe a modification and extension of of the CAREX system in order to calculate the number of workers exposed to carcinogens in Costa Rica. It is the first use of CAREX outside Europe (TICAREX) in Costa Rica, Central America, for 27carcinogens and 7 groups of pesticides thought to be of interest for the country, with separate estimations for men and women. The most frequent agents of exposure for the 1.3 million workers of Costa Rica were solar radiation (333,000 workers); diesel exhaust (278,000); paraquat and diquat (175,000); environmental tobacco smoke (71,000); hexavalent chromium compounds (55,000); benzene (52,000); mancozeb, maneb and zineb (49,000); chlorothalonil (38,000); wood dust (32,000); quartz (27,000); benomyl (19,000); lead and its inorganic compounds (19,000); tetrachloroethylene (18,000); and polycyclic aromatic hydrocarbons (17,000). Owing to the different occupational distribution between the genders, exposures to formaldehyde, radon and methylene chloride were more frequent than pesticides, hexavalent chromium, wood dust, and quartz in women. Agriculture, construction, personal and domestic services, manufacture of wood products, mining, forestry, fishing, manufacture of electrical products, and bars and restaurants were sectors with frequent exposures. Substantial reduction of occupational and environmental exposures to these agents would significantly improve public and occupational health. Reduction of occupational exposures is usually also followed by improvement of environmental quality. Monitoring of exposures and health of workers and the general public is an essential element in the control of environmental contamination and human exposures

Paraquat in developing countries.

The herbicide paraquat is considered safe by industry and the bulk of regulators worldwide. However, determinants of exposure from 30 years ago persist in developing countries. Little is known about systemic absorption from occupational exposures. The relationships between exposure determinants, levels of external exposure, biomarkers of exposure, and outcomes are not clear. High rates of severe acute poisonings have been documented. In addition, topical injuries occur in as many as 50% of exposed workers. Non-worker populations are also at risk, particularly children. Long-term and delayed health effects include Parkinson's disease, lung effects, and skin cancer. Regulatory agencies have not fully recognized either the inherent toxicity of paraquat or the particular risks derived from exposures in developing countries. Independent risk assessment in the developing-country context and application of the precautionary principle are necessary to prevent adverse effects of dangerous pesticides in susceptible populations.

Hazardous pesticides in Central America.

Pesticides are an extensively documented occupational and environmental hazard in Central America. Yet, severe problems persist. Toxic pesticide use in the Region increased during 1985-1999. High exposure levels and ineffectiveness of personal protective equipment evidence the difficulties for risk reduction. Acute poisonings remain a severe problem. Delayed and/or long-lasting health effects include dermatoses, cancer, and genotoxic, neurotoxic, and respiratory effects. The use of hazardous pesticides persists through deficiencies in government-driven assessment and risk management; excessive focus on regional harmonization; short-term economic interests; strong links between industry and governments; aggressive marketing; weak trade unions; and failure of universities to reach decision makers. Regulation based on local data is lacking. An agreement of the Ministries of Health for restricting the most toxic pesticides in Central America has potential for progress. The most effective way to reduce risk is to greatly reduce pesticide use. Actions needed include development of multidisciplinary strategies for local studies on health and environmental impact of pesticides; development of sustainable nonchemical agricultural technologies; evaluation of interventions; extending and sharing of expertise within the Region; strengthening of unions and communities; and redefining the role of industry toward development of safer products, with responsible marketing and reliable information.