Low Cd content emitted by humans into the atmosphere

¹ School of International Economics, Shaanxi Institute of International Trade & commerce, Xi’an 712046, China
² Ecology and Environment College, Shanghai Ocean University, Shanghai 710123, China
³ North China Sea Environmental Monitoring Center, SOA, Qingdao 266033, China
⁴ The Fu Foundation School of Engineering and Applied Science, Columbia University, 10025, USA

^a dfyang_dfyang@126.com

Abstract

According to the data in May, September and October 1993, the variation range of Cd content in the water body of Jiaozhou Bay was 0.07-0.23μg/L, which conforms to the national water quality standard of Class I. It indicated that in May, September and October, the water in the entire water area of Jiaozhou Bay was not contaminated by Cd content. In May, the variation range of Cd content in the waters of Jiaozhou Bay was 0.09-0.18μg/L. In the coastal waters of the north of Jiaozhou Bay, the Cd content reached a relatively high value, which was 0.18μg/L. In September, the variation range of Cd content in the waters of Jiaozhou Bay was 0.07-0.23μg/L. In the coastal waters of the east of Jiaozhou Bay, the Cd content reached the highest value, 0.23μg/L. In October, the variation range of Cd content in the waters of Jiaozhou Bay was 0.08-0.18μg/L. In the coastal waters of the east of Jiaozhou Bay, the Cd content reached a relative high value, 0.18μg/L. In terms of Cd content, the water quality of Jiaozhou Bay had reached high quality. The water was clean, and it was not polluted by Cd content at all. The Cd content in the waters of Jiaozhou Bay mainly came from two sources, the transport of surface runoff and the transport of atmospheric deposition. The Cd content from surface runoff transportation was 0.18μg/L, and the Cd content from atmospheric deposition transportation was 0.18-0.23μg/L. The Cd content transported by atmospheric deposition was very close to the Cd content transported by surface runoff, and was very low, ranging from 0.18 to 0.23μg/L, far less than 1.00 μg/L. This revealed that the humans had realized the importance of environmental protection, and the emissions to the environment were very low. The atmosphere, land and sea were not polluted by Cd content. The Cd content transported by atmospheric deposition 0.18-0.23μg/L ≥ the Cd content transported by surface runoff 0.18μg/L, which indicated that the Cd content was mainly discharged into the atmosphere by humans and then deposited on the land.