Anticorrosion chemicals, ancient Arkansas rock, stowaway species and more in this week’s news

Corrosion inhibitors taint water British researchers have found corrosion-inhibiting chemicals used in dishwashing detergents, auto antifreeze and other products throughout the environment — even in water coming out of kitchen taps. Dishwashing appears responsible for at least 30 percent of the benzotriazoles in water, the researchers report online April 4 in Environmental Science & Technology . Although the corrosion inhibitors are not acutely toxic, the authors note that few studies of chronic exposure exist — none involving fish. The scientists conclude that exposures should be minimized until the chemicals’ long-term safety can be confirmed. — Janet Raloff Ancient Arkansas Parts of southwestern Arkansas may be more than 3 billion years old, a finding that has geologists rethinking how continents are put together. Geochemical studies of rocks from Pike County, Arkansas, suggest the rocks are far older than once thought; later pulses of molten rock from deep in the crust altered their chemistry to make them appear younger. The discovery suggests that ancient crust may lurk in the centers of more parts of continents than researchers had thought, a team led by William Griffin of Macquarie University in Australia reports in an upcoming issue of the Geological Society of America Bulletin . — Alexandra Witze Fossil fuels and behavioral problems A new study links exposure in the womb to polycyclic aromatic hydrocarbons — pollutants emitted by traffic and other sources of fossil fuel combustion — with symptoms in 5- to 7-year olds of anxiety, depression and attention problems. Scientists at Columbia University tracked DNA markers of PAH exposure in umbilical cord blood from 252 mother-infant pairs. Children in the upper quartile of PAH exposure had 40 percent higher scores on measures of behavioral problems that might interfere with learning, the scientists reported online April 12 in Environmental Health Perspectives . An earlier study by the group linked PAH exposure in the womb to IQ deficits. — Janet Raloff Zapping ship stowaways Engineers in Singapore have developed a technology to disinfect the ballast water that ships pick up at ports around the world. Although ballast water is important for maintaining the stability of tankers on the high seas, it inevitably moves plants and animals around the world, contributing to invasions by ecosystem-destabilizing species. The new electrochemical technique generates chlorine or other disinfectant compounds from sea water. Six watt-hours of power per cubic meter of treated water killed E. coli and other germs, the researchers report online April 6 in Marine Pollution Bulletin . Bigger illegal immigrants would be collected with sieves and removed. — Janet Raloff

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