Environmental Engineering Reference
In-Depth Information
Measurements of Heavy Metals in Dry and Wet
Deposition in São Paulo City
Ana Paula G. Fontenele, Adalgiza Fornaro, and Jairo J. Pedrotti
Introduction
In Metropolitan Area of São Paulo (MASP), the air contamination is caused mainly
by gases and particulate matters released by the large fleet of light and heavy
vehicles, but also by industrial processes
[1]
. Besides environmental consequences,
the particulate matters, (PM), have been linked to health damage because they
contain a wide range of toxic metals and organic contaminants. Among the (PM)
constituents, heavy metals have been investigated due to the elevated toxicity to
living organisms. Some metals, like copper and zinc, are essential nutrients but they
can cause harmful effects depending on their concentration levels. Cadmium is
considered very toxic, classified as potential carcinogenic. Lead is also recognized
by the World Health Organization (WHO) as one of the most dangerous chemical
element for the human health. In MASP, epidemiological studies show that
increases in hospital admissions and mortality have been associated with air
pollution episodes
[2]
. Aerosols can be removed from the atmosphere by two main
pathways: dry and wet deposition, depending on their physical characteristics such
as particle size, vapor and solubility pressure in water, and chemical composition
[3]
. In this study the concentrations of zinc, copper, cadmium and lead in fine
(PM
2.5
) and coarse (PM
2.5-10
) particle material in São Paulo rainwater were
determined. The aim is to evaluate the extension of the contamination of the São
Paulo city atmosphere as well as to identify the main deposition route of heavy
metals in this urban area.
