Diagnosis of contaminated areas by final disposal of solid waste in the municipality of Paço do Lumiar (MA), Brazil

ABSTRACT The final disposal of solid waste is considered a potential source of contamination and has been highlighted due to the environmental problems and socioeconomic factors that it can generate. The municipality of Paço do Lumiar, Maranhão, uses a garbage dump as a way of disposing urban solid waste, even after the deadline for the end of dumps in Brazil, as established by the National Solid Waste Policy, Federal Law No. 12,305, dated August 2, 2010. As a result, the objective of this study was to detect areas contaminated by disposal of solid waste in Paço do Lumiar, based on the Workshop Management of Contaminated Areas’ methodology, a part of the project CETESB/GTZ (1999), using the environmental compartments soil and surface water as objects of analysis. Thus, it was found that the garbage dump has contributed to the contamination of soil with heavy metals in the place of provision and 200m to its downstream, which can mean potential contamination of ground water due to the local geology and the fact that sandy soil facilitates the process of transporting contaminants. The analysis of the surface water revealed that the disposal of solid waste can contribute less than other sources of contamination, highlighting in this context those generated by the communities that occupy the basin. Therefore, as the verified contamination compromises some land uses (residential and agricultural), further studies may contemplate the remediation process of these contaminated areas according to the CTESB/GTZ (1999) material for stablishing measures to minimize this region’s environmental impacts.

摘要：固体废物最终处置被视为潜在污染源，其引发的环境问题与社会经济影响因素使其受到广泛关注。巴西马拉尼昂州帕苏杜卢米亚尔市仍采用露天垃圾场处置城市固体废物，即便根据2010年8月2日颁布的《国家固体废物政策》（第12305号联邦法律）要求，巴西已到取缔露天垃圾场的时限。

本研究旨在基于隶属于CETESB/GTZ（1999）项目的污染区域管理研讨会（Workshop Management of Contaminated Areas）方法体系，以土壤与地表水作为分析的环境介质（environmental compartments），识别帕苏杜卢米亚尔市范围内受固体废物处置污染的区域。

研究结果显示，该露天垃圾场及其下游200米范围内的土壤已受到重金属污染；结合当地地质条件与砂质土壤易促进污染物迁移的特性，该区域存在地下水遭受潜在污染的风险。对地表水的分析表明，固体废物处置对地表水的污染贡献弱于其他污染源，本研究背景下的主要污染源为流域内聚居社区产生的污染物。

鉴于已验证的污染已对居住与农业用地等土地利用类型造成不利影响，未来可参考CETESB/GTZ（1999）的相关资料开展受污染区域修复工作，制定以降低该区域环境影响为目标的治理措施。