Objective To study the pollution level of microcystin and its effect on the liver function of residents living around Dianshan lake.
Methods Selecting 5 sites in east, west, north, south and middle in the lake as the monitoring points, samples were collected during May to September in 2008, then total phosphorus(TP), total nitrogen(TN), pH, turbidity, COD and microcystin-LR (MC-LR)were continually analyzed. At the same period, a serum epidemiological study was carried out in 120 local residents around the lake who lived there for more than 10 years. Another 122 factory workers were chosen as control whose working and living environment were not affected by Dianshan lake.
Results In the water samples, pH was 7.94, turbidity was 20.92, COD was 5.28mg/L, TP was in the level of 0.06 to 0.31μg/ml, TN was 0.2 to 6.3μg/ml, and TN/TP ratio was ranged between 0-54.4. The water samples also showed the Dianshan lake was polluted by MC-LR as its concentration reached 0.0085μg/L. It was more serious in summer and autumn. Compared with control group, the activity of AST, LDH and GGT in the serum of local residents were all higher with significant difference(P < 0.05), but ALT showed no difference between the two groups(P=0.574).
Conclusion Dianshan lake have been polluted by MC-LR, The liver function of residents living around Dianshan lake for a long time may be affected by the pollution.
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