Hexachlorocyclohexane contamination in an Urban area of Rio De Janeiro, Brazil

• Published in: Environment international 1996, Vol.22 (3), p.289-294
• Main Authors: Oliveira, R.Maria, Brilhante, O.Magno
• Format: Article
• Language: English
• Subjects: Air pollution; Applied sciences; Chemical plants; Contamination; Exact sciences and technology; Gas chromatography; Global environmental pollution; Groundwater; Pollution; Q1
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/0160-4120(96)00014-1

A plant belonging to the Ministry of Health, where hexachlorocyclohexane (HCH) was produced, was closed down in 1955. Located in Duque de Caxias, Rio de Janeiro, the plant was left with its production exposed, which ended up being swept by the rain, wind, or taken by local people, more than 1000 individuals. A daycare center, Cristo Redentor, houses 400 children that, until recently, still received milk, fruits, and vegetables produced in the region. Four HCH isomers, α, β, γ, and δ, were analyzed by high resolution gas chromatography in soil, water, and pasture samples. An extremely high level of surface soil contamination (order of hundreds of mg/kg) was found in the area up to 100 m away from the old plant. Subsurface soil samples, collected on vertical profiles of about 2 m deep, showed lower contamination in the deepest layer. Water samples collected from the groundwater showed the presence of all four isomers, ranging from 0.02 to 1.3 μg/kg; preliminary results on ‘Pernambuco’ grass ( Paspalum sp), used as cattle food, presented high HCH isomer concentrations (order of thousands of μg/kg) even at distances farther than 1.1 km from the old plant. These results show that the high risk of contamination is restricted to the population (four families) living in the area within the 100 m radius, and to the consumption of food and subproducts produced there.