Atrazine and Nutrients in Precipitation: Results from the Lake Michigan Mass Balance Study

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• 作者：Sondra M. Miller ; Clyde W. Sweet ; Joseph V. DePinto ; and Keri C. Hornbuckle
• 刊名：Environmental Science & Technology
• 出版年：2000
• 出版时间：January 1, 2000
• 年：2000
• 卷：34
• 期：1
• 页码：55 - 61
• 全文大小：167K
• 年卷期：v.34,no.1(January 1, 2000)
• ISSN：1520-5851

文摘

Atmospheric deposition of anthropogenic air pollutantscontributes to degradation of water quality in the Great Lakesand other water bodies and is indicative of atmosphericpollution. In this paper, we discuss deposition of three airpollutants: atrazine; total phosphorus; and nitrogen(total Kjeldahl nitrogen and nitrate) to Lake Michigan.Throughout 18 months in 1994-1995, over 600 atmosphericsamples (gas, particulate, and precipitation combined)were collected and analyzed for persistent organic pollutantsand nutrients. Here the measurements and modeleddeposition estimates are presented for atrazine, phosphorus,and nitrogen. Results indicate that concentrations ofatrazine in precipitation have remained constant over 5years (0.10-0.40 g L^-1), consistent with the nearly constantsales rate of the herbicide over that time period. Actualloading of atrazine to the lake was less in 1994-1995 (1.04× 10³ kg y^-1) than in 1990-1991 (2.6 × 10³ kg yr^-1). Thisdifference in loading is due to lower overall precipitation in1994-1995. Phosphorus concentrations in precipitation,on the other hand, have decreased from an average of 57g as P L^-1 in 1976 to an average of 6.36 g as P L^-1for 1994-1995. Nitrate deposition has decreased by a small,but not statistically significant, amount since the late1970s.