Seasonal-temporal variations of Cd contents on in Jiaozhou Bay 1984-1988

This paper analyzed the seasonal and spatial variations of Cadmium (Cd) in Jiaozhou Bay during 1984-1988. Results showed that Cd contents in Jiaozhou Bay in 1984, 1985, 1986, 1987 and 1988 were 0.06-0.20 εg L⁻¹, 0.03-0.44 εg L⁻¹, 0.01-6.48 εg L⁻¹, 0.07-0.12 εg L⁻¹, and 0.03-1.07 εg L⁻¹, respectively. The pollution levels of Cd in Jiaozhou Bay in 1984, 1985, 1986, 1987 and 1988 were Grade I, I, I-III and V, I, and I-II, respectively. The seasonal variation of Cd contents was summer > spring > autumn. The pollution level of Cd during 1984-1985 was still slight, while the pullution level during 1986-1988 was tending to be aggravating to be slight/moderate. In general, the source input of Cd to this bay was increasing during the five-year period, and the pollution level of Cd would be aggravating since the water environmental capacity was not infinite. As a whole, source control was one of the basic contourmeasures for pollution control and environmental remediation in this bay. (paper)