Contamination and impacts of new antifouling biocide lrgarol-1051 on subtropical coral reef waters

Coral reefs are deteriorating worldwide due to various stresses, including pollution of hazardous chemicals such as antifouling chemicals. Occurrence and impacts of a new antifouling biocide Irgarol-1051 [2-methylthio- 4-tert- butylamino -6-cyclopropylamino -s-triazine] have been studied in coral reef waters around Okinawa Islands, Japan. The average concentration of Irgarol detected at commercial and fisheries Ports was 24.70 +/- 9.88 ng/L. In Naha Bay, the average concentration of Irgarol was 10.00 +/- 12.98 ng/L. The average level detected around the Ports has already approaches the environmental risk limit for the marine organisms. Irgarol was detected in waters at the frequency of 92.3% [24/26] of the total samples collected during two sampling campaigns [September and December, 2007] at the Ports. In Naha Bay, Irgarol was detected by 40.5% [17/42] of the total water samples collected monthly from Sep., 2007 to Feb., 2008, indicating that Irgarol is widely detected along the coastal shorelines of Okinawa Island. The ecotoxicological study revealed that the rate of photosynthesis in the coral Galaxea fascicularis was significantly reduced by 18% and 121% relative to control when the corals were exposed to 1000 and 10,000 ng/L of Irgarol, respectively. The calcification rate dropped by 98.3% relative to control when the corals were exposed to 10,000 ng/L of Irgarol. The results of the present study report the wide occurrence of new antifouling biocide Irgarol around coastal areas of Okinawa Island. However, the contamination does not pose serious threat on the photosynthesis and calcification of corals under short term exposure [96 h]

comparative study of trihalomethanes in drinking waters

The purpose of this study was to assess exposure of four trihalomethanes [chloroform, bromodichloromethane, dibromochloromethane and bromoform] in drinking waters of Okinawa Island and Samoa. Trihalomethanes compounds were determined in the drinking water samples that were collected from the selected consumption sites and treatment plants of both Okinawa and Samoa in 2003-2004. The Chatan and Nishihara Water Treatment Plants [Okinawa] uses both ozonation and chlorination for primary and secondary disinfection. For Samoa Water Treatment Plants only chlorination is used as primary disinfection. Results showed that the mean concentration of trihalomethanes from treatment plants in Okinawa ranged from 0.30 +/- 1.81 microg/L to 11 +/- 2.68 microg/Land from the consumption sites ranged from 2.08 +/- 0.32 microg/L to 19.39 +/- 100 microg/L. In comparison, the mean concentration of trihalomethanes from the treatment plants in Samoa ranged from 226 +/- 81.2 microg/L to 267 +/- 92.3 microg/L and from the consumption sites were in the ranges 212 +/- 101 microg/L to 387 +/- 125 microg/L. Brominated compounds were commonly seen in all samples collected in Okinawa. Among the trihalomethanes compounds, chloroform was the common detected trihalomethanes in the samples collected from Samoa. The trihalomethanes levels in all samples collected in Okinawa and Samoa were generally below the guideline values in Japan, but some samples displayed levels which exceeded the level of Japan Water Quality and WHO Standards for chlorinated and brominated compounds