RESUMO
Groundwater in the Yucatan State is the only source of water. The karst aquifer in Yucatan is vulnerable to pollution. Anthropic activities in Yucatan, such as pig farming, are usually related to high wastewater discharges and water pollution. Administrative and logistical issues in developing on-site sampling to evaluate water quality are common in Mexico. The RENAMECA database provides official data related to groundwater quality. However, no analysis based on this database has been reported. A groundwater quality evaluation based on five reference pig farms and the effect of spatial and temporal anthropic activities in the study area was developed. Eighteen wells based on their location concerning the selected pig farms were studied. On-site sampling and laboratory analysis of the supply water and wastewater in the study case farm were done. Fecal coliforms (FC) values (maximum 2850 MPN [100 mL] -1) in most cases for supply water wells exceeded the allowed limit by NOM-127-SAA1-2021. The year of monitoring was significant (P < 0.05) on FC concentrations. Population density and the proximity of wells to population centers affect negatively the presence of total dissolved solids (TDS) and total nitrogen (TN). TDS (maximum value 2620 mg L -1) and phosphorus presence could be related to agricultural activities, human settlements, and local aquifer conditions. A local wastewater treatment issue is evident. Groundwater is not quality for consumption without treatment. Regarding the issues in on-site water monitoring, database analysis provides an approximation of the real situation of groundwater quality.
RESUMO
The karstic aquifer of Yucatan features a high permeability, therefore, all contaminants placed in the soil surface, can reach it through infiltration along with the rain water. The purpose of the present study is to determine the spatial distribution of the aromatic hydrocarbons in the underground water of Merida City. Fifty wells inside the city were sampled. The sampling took place during the dry season, from October 2007 to March 2008. Liquid-liquid Hydrocarbon extraction was performed using hexane and purification was made by previously packed chromatography columns. Regarding the occurrence of polynuclear aromatic hydrocarbon (PAHs) traces, 28 water samples (56%) contained residues of these compounds. The following PAHs presented the highest concentrations: benzo(a)anthracene y benzo(k)fluoranthene 13.26 and 7.88 µg L-1 respectively. Only three of the sampled wells showed levels above those allowed by EPA and WHO norms. The origin of these compounds is mainly pyrogenic.
Assuntos
Água Subterrânea/química , Hidrocarbonetos Policíclicos Aromáticos/química , Cidades , México , Chuva , Estações do Ano , Solo/química , Poluentes do Solo/químicaRESUMO
In this study, 24 breast milk samples, obtained from rural Maya women, from municipalities of Yucatan, Mexico, were analyzed for organochlorine pesticide (OCP) residues by gas chromatography. Recent studies have shown that Maya communities have a poor perception about the proper usage and handling of OCP. The karstic soil in this area has a high vulnerability to groundwater pollution by the use of OCP in agriculture and livestock activities. The impact of the ecosystem on human health is much more critical due to the prevailing poverty and a very low educational level of these communities. About 30% of the Maya population consumes water directly from contaminated wells and sinkholes, resulting in a chronic exposure to OCP. The samples served to identify and quantify high levels of OCP residues (18.43 mg/kg of heptachlor epoxide and 1.92 mg/kg of endrin in the metropolitan zone; 2.10 mg/kg of dieldrin, 0.117 mg/kg of endosulfan II, 0.103 mg/kg of heptachlor, 0.178 mg/kg of endrin, and 0.127 mg/kg of endrin aldehyde in the main agricultural zone and on the west coast). The detected levels of OCP residues are a major concern and represent a potential risk to women and children in the region. This could be associated with the high rates of cervical uterine and breast cancer mortality in Yucatan. Thus, regulations on the usage of OCP and their enforcement are necessary, and it is important to establish a yearly monitoring program for OCP residues in breast milk and groundwater, as well as to implement health promotion programs for women in particular and the general population in general.