Current levels of OCPs in sediments: An environmental risk assessment for a wetland of international importance in the southern Gulf of Mexico

Coastal wetlands in the southern Gulf of Mexico are continually subjected to various anthropogenic pressures, some of which are associated with agricultural activities in the region, where organochlorine pesticides (OCPs) are still used. This study aimed to record the current presence of these compounds in sediments and identify the influence of organic matter content and grain size on their distribution in the Alvarado coastal lagoon, a Ramsar site of international importance. OCPs were quantified by gas chromatography-tandem mass spectrometry (GC-MS/MS); ∑7OCPs ranged from 47.7 to 54.7 ng g-1, with endrin aldehyde being the most abundant compound. The recent addition of p,p'-DDT was also highlighted. Spearman's correlation matrix and principal component analysis revealed that the accumulation and spatial distribution of these pesticides in sediments were associated with silt particles. The estimated additive risk ratios suggest a low to high level of ecotoxicological risk, primarily due to p,p'-DDT and dieldrin, the latter being the most threatening to benthic organisms. The data obtained in this work could contribute to public policy actions focused on mitigating and preventing ecosystem risk of OCPs, for better management of anthropogenic activities in this Mexican coastal wetland.