Concentrations of chromium and copper in air particulates in Dhahran, Saudi Arabia

Abstract EN

Total suspended (TSP) and inhalable (PM 10) particulates were collected on quartz filter papers using Hi-Vol samplers.

These samples were digested in aqua regia and perchloric acids for three hours.

Air particulates collected in 1982 at the same location were prepared similarly.

Concentrations of chromium and copper were determined in the aliquot samples using an inductively coupled argon plasma analyzer (1CAP).

Significant (P < 0.01) daily variations were found in chromium and copper concentrations (expressed as ng m-3) in air particulates.

The arithmetic mean concentration of chromium in the TSP increased sharply from March 1991 through June-July, decreased rapidly in August, remained constant through October, decreased again through December, 1991 and remained statistically similar through March 1992.

The arithmetic mean concentration of chromium in the inhalable fraction (PM 10 particulates) closely followed this pattern.

The copper distribution patterns both in TSP and PM 10 particulates from March through November, 1991 was similar to that of chromium, however, copper increased sharply from December 1991 through March 1992.

Concentrations of chromium and copper in TSP and PM 10 particulates gradually decreased from April through October when the analytical data were normalized for particulate mass.

The mean concentrations of chromium and copper found in TSPs collected in May, June, and October 1991 were compared with samples collected at the same location in 1982.

Copper and chromium were significantly (P < 0.01) higher in the TSP samples collected in May and June 1991 than those from 1982.

However, statistically similar concentrations of copper and chromium were found in the TSPs collected in October 1991 and 1982.

From the foregoing, it could be concluded that the Gulf Crisis had elevated chromium and copper concentrations in the air particulates at Dhahran.