Urban occupation interference in the distribution of Persistent Organic Pollutants in mangrove

ABSTRACT

Mangrove areas are subject to human pressure, depositional ecosystem, and their sediments contain records of environmental history. The Itaoca Environmental Protection Area was recently created in the mangrove region of São Gonçalo. This site received domestic waste over 28 years. The sedimentary profile determined geochronology and quantified persistent organic pollutants, such as polyaromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides. Polyaromatic hydrocarbons had a pyrogenic origin with moderate concentrations, except for dibenzo [a,h] anthracene, a carcinogenic compound that exceeded the limit effect level. The sedimentary record corresponding to the period prior to the dump suggested that polyaromatic hydrocarbons were linked to the burning of wood by potteries. Perylene was a good marker for the reduction of plant biomass, suggesting an association with the suppression of mangroves during the occupation. In the period prior to the dump, before 1976, the contamination of the sediment by organochlorine pesticides, such as [2,2-bis (p-clorofenil) −1,1dicloroetileno] (primary metabolite of [1,1,1-tricloro-2,2-bis (p-clorofenil) etano]), was linked to public health campaigns to combat the malaria mosquito, exceeding the limit effect level values. During the period of activity of the dump, the increase in [2,2-bis (p-clorofenil) −1,1dicloroetileno] values coincided with the banning of [1,1,1-tricloro-2,2-bis (p-clorofenil) etano], suggesting its irregular disposal. polychlorinated biphenyls were below limit effect level concentrations, but similar to those found in industrial dumps in other countries. Persistent organic pollutants proved to be efficient anthropic markers of urban occupation and contamination caused by the landfill. As it is located in an environmental protection area, an immediate resumption of the remediation process is necessary to interrupt the contamination process of the Environmental Protection Area in question.

Keywords:
dump; POPs; PAHs; DDE; PCBs; mangrove; environmental protection area