BRITISH COLUMBIA: A study has revealed high levels of persistent chemicals in the bodies of endangered killer whales. According to researchers in the Canadian province of British Columbia, 4-nonylphenol was found in the whales studied. (4 np) chemicals found. The 4 np chemical is often used to make tissue and paper, but it is also used in soaps, detergents and textiles. This chemical is used to treat water. Can enter the sea in the form of sewage from plants or industrial waste. Because killer whales are at the top of the food chain, they eat small organisms contaminated with this chemical.