Toxicity of metal pyrithione photodegradation products to marine organisms with indirect evidence for their presence in seawater.
We evaluated the acute toxicities of the metal pyrithiones (MePTs)--copper pyrithione (CuPT) and zinc pyrithione (ZnPT)--to four species of marine algae and a marine crustacean (Tigriopus japonicus). We also performed acute toxicity tests using six of the main MePT photodegradation products: pyridine-N-oxide (PO); 2-mercaptopyridine (HPS); pyridine-2-sulfonic-acid (PSA); 2-mercaptopyridine-N-oxide (HPT); 2,2'-dithio-bis-pyridine ([PS](2)); and 2,2'-dithio-bis-pyridine-N-oxide ([PT](2))-and three marine organisms representing three trophic levels: an alga (Skeletonema costatum), a crustacean (T. japonicus), and a fish (Pagrus major). The acute toxicity values (72-h EC(50)) of CuPT, ZnPT, HPT, (PT)(2), (PS)(2), HPS, PO, and PSA for S. costatum, which was the most sensitive of the test organisms to the chemicals tested, were 1.5, 1.6, 1.1, 3.4, 65, 730, >100,000, and >100,000 microg l(-1), respectively. CuPT was detected in the growth media used for S. costatum tests and in seawater containing HPT or (PT)(2); the concentration of CuPT in seawater containing HPT was highly dependent on the Cu(2+) concentration. These results indicate that in the presence of sufficient Cu(2+), the toxicities of HPT and (PT)(2) should be assessed as CuPT because in Japan MePTs are most frequently used as antifouling booster biocides in conjunction with cuprous oxide.
Onduka
Toshimitsu
T
National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, Japan. onduka@affrc.go.jp
Mochida
Kazuhiko
K
Harino
Hiroya
H
Ito
Katsutoshi
K
Kakuno
Akira
A
Fujii
Kazunori
K
D000818:Animals; D003445:Crustacea / Q000187:drug effects* / Q000254:growth & development; D017377:Diatoms / Q000187:drug effects* / Q000254:growth & development; D004784:Environmental Monitoring; D007564:Japan; D007928:Lethal Dose 50; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000032:analysis / Q000528:radiation effects / Q000633:toxicity*; D010473:Perciformes / Q000254:growth & development*; D010782:Photolysis; D011725:Pyridines / Q000032:analysis / Q000528:radiation effects / Q000633:toxicity*; D012623:Seawater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000528:radiation effects / Q000633:toxicity*
D009942:Organometallic Compounds; D011725:Pyridines; D014874:Water Pollutants, Chemical; C487833:copper pyrithione; C010423:pyrithione zinc