FORENSIC AND ENVIRONMENTAL ANALYSIS OF LEAD DISTRIBUTION IN ERIE AND NIAGARA COUNTY SOILS

A variety of potentially hazardous metals are commonly found in soils. Depending on the concentration, people especially children, who are exposed to these metals, may be at risk of serious health problems. The goal of this study is to examine the variations in lead levels in public areas throughout western New York and compare them to the bedrock and surface geology. Our hypothesis is that there is more lead in urban areas and less in suburban areas, and that the major sources for lead are anthropogenic. In addition, we hope to use trace elements in the soils to differentiate locations, which has several forensic applications.

Children are very susceptible to lead poisoning because it can accumulate in their bones as their bodies grow and develop. High levels of lead in children may cause serious health problems, including lower intelligence and nerve damage.

Soil samples from public playgrounds, schools and beaches in city of Buffalo and the surrounding suburbs are being collected and analyzed using a Niton field portable x-ray fluorescence (FPXRF) unit. The Niton FPXRF spectrometer uses an x-ray tube to irradiate samples. The incident x-rays interact with the atomic structure of the elements in the sample, knocking electrons from the inner orbitals. This causes secondary x-rays to be generated as outer shell electrons release energy to fall into new ground states. The energy of the x-ray generated will be equivalent to the energy difference between the two shells. Since each element has a distinctive arrangement of electrons, the x-rays released will be unique to that element and it is possible to determine the elemental composition of a sample.

For this study, soil samples were collected in the field using a 15 cm x 15 cm sample area to a depth of around 3 cm. Each sample was placed overnight in a drying oven and then homogenized. The samples were analyzed in Mylar capped sample holders using Niton FPXRF unit and data collected for 120 seconds.

The samples tested thus far have been from urban and rural areas in Erie and Niagara counties. The general pattern of the results for Erie County shows significantly higher lead levels in the City of Buffalo (370 ppm) and lower levels in the outlying suburbs (ranging between 30 and 70 ppm). Another area with high lead levels occurs in Niagara County, near the former Love Canal site (170 ppm).