Distribution of lead in urban roadway grit and its association with elevated steel structures.
In an effort to determine the source of exterior lead contamination, we investigated the concentration of lead in roadway grit along major thoroughfares in New York City and in certain areas under elevated steel structures supporting elevated rails. Such structures represent only one source of lead in roadway grit. While data revealed that the median lead concentration in roadway grit did not exceed the standard for a lead hazard in bare residential soil in any borough, the limit of 400 microg/g was exceeded 22%, 18%, 10.5%, and 7.7% of the time in Manhattan, Brooklyn, The Bronx, and Queens, respectively. The second part of the study revealed the presence of high concentrations of lead in roadway grit directly under elevated steel structures. The differences in the concentration of lead in roadway grit under steel structures in comparison to areas in NYC not near elevated rails was statistically significant. Of the eight sites studied from 225 total samples, the median roadway grit lead level was 340 ppm, while the level under steel structures was 1480 ppm. Preliminary efforts to determine particle size distribution revealed that 84% of the particles were in the range of 125-500 microm, but the highest concentration of lead was in the smallest fraction analyzed (<63 microm). Lead contamination of roadway grit from restoration of elevated painted steel structures is a public health problem as these lead particulates get re-suspended in the ambient environment and are wafted and tracked into residences.
Weiss
Arlene L
AL
Environmental Medicine Inc., 263 Center Avenue, Westwood, NJ 07675, USA. aweiss@envmed.com
Caravanos
Jack
J
Blaise
Marc J
MJ
Jaeger
Rudolph J
RJ
D000393:Air Pollutants / Q000032:analysis; D001108:Architecture; D004391:Dust; D004784:Environmental Monitoring; D007854:Lead / Q000032:analysis*; D009519:New York City; D010316:Particle Size; D012989:Soil Pollutants / Q000032:analysis; D013232:Steel; D014507:Urbanization
D000393:Air Pollutants; D004391:Dust; D012989:Soil Pollutants; D013232:Steel; D007854:Lead