Establishing a scenario of exposure to environmental toxins associated with nephropathies in agricultural areas of Costa Rica based on Geological Medicine

Abstract

Abstract Chronic Kidney Disease (CKD) of unknown origin has caused serious public health problems in specific countries in the word, such as, Sri Lanka, India and Mesoamerica. Particularly in Costa Rica the pathology and linked mortality are concentrated in the north pacific region from the country. Affected people are found predominantly in rural agricultural areas with warm climate and low altitude and to a much lesser extent in hilly elevated areas; however, the full geographic extent of the disease is still unclear. The objective of this research is to determine a scenario of exposure to toxicants in populations with high numbers of cases of CKD. Explanatory variables for the high rate of CKD were determined by means of a Poisson multivariate regression analysis at a national level. The environmental variables included hectares of cultivated and burned sugarcane, atmospheric temperatures, relative humidity, arsenic in water for human consumption, speed and direction of winds, annual average precipitation, and geographical location with respect to alti- tude. Heavy metals, including transition metals and metalloids such as arsenic, cadmium, mercury, lead, vanadium, and silicon, which even at low concentrations have the potential to cause nephrotoxicity via chronic exposure, were quantified in the soils in areas with the highest prevalence of the disease in the country. According to this quantifica- tion and analysis, these metal(loid)s may have causal relevance in the pathology of CKD. The statistical, geographical and laboratory analy- ses determined that population exposure to environmental toxicants is seasonal, occurring under the convergence of annual climatic phenomena.