Lead Contamination of Soils in Belize City, Belize, Central America

摘要

In order to assess the amount and distribution of lead pollution in soils in Belize City, Belize, seventy-five samples were collected from three distinct areas around the city (roadsides, houses, and playgrounds and schools). This study has provided data to establish the first soil lead database for Belize City, Belize. The soil samples generally exhibited pH values above 7, less than 18% organic matter, and more than 50% sand was found in 92% of the samples. These physical and chemical characteristics prevent the lead from accumulating in the upper layers of soil. However, high or hazardous levels were found in all sample categories. In the schoolyards and playgrounds category, the levels range from 3 ppm to 780 ppm, and average 131 ppm. The roadside samples had a range of 3 ppm to 5450 ppm, and average 445 ppm. The housing samples had the highest concentrations, with the range from 9 ppm to 104, 500 ppm and an average of 638 ppm. The geographic distribution of lead within the city appears to be somewhat random, although the most contaminated areas are generally in the south part of the city. The distance to potential source of contamination, for example peeling paint or a road, affects lead concentration, as does percent of organic matter in the soil. The physical characteristics that normally aid in the retention of lead in soil are not generally present in Belize City; however, the lead levels are dangerously high.