01
Feb
(Beyond Pesticides, February 1, 2007) Thirty-five years after the banning of DDT, extremely high concentrations of the pesticide are being found in fish caught in California’s Los Angeles county waters. According to a newly released federal survey by the National Oceanic and Atmospheric Administration (NOAA) and Environmental Protection Agency (EPA), the fish caught in the area contain the world’s highest-known DDT concentrations. The survey was conducted in order to update health advisories on which fish are unsafe to eat and to help EPA decide whether to attempt a costly operation to reduce continued contamination from a deposit of DDT on the ocean floor. The findings contradict the belief held by some scientists that DDT on the ocean floor has been breaking down into less-toxic compounds and would soon disappear from marine life. The contamination, most severe in the middle of San Redondo Bay, stems from a 100-ton deposit of DDT released by the Montrose Chemical Co. beginning in the late 1940s, which still covers several square miles of the ocean floor. The pesticide manufacturer had a plant near Torrance, California, from 1947 to 1971, releasing about 2,000 tons of DDT into county sewers that subsequently emptied into the ocean. The […]
Posted in California, Chemicals, DDT, State/Local, Water, Wildlife/Endangered Sp. | No Comments »
25
Jan
(Beyond Pesticides, January 25, 2007) The commonly used herbicide atrazine has been found to have negative biological effects on phytoplankton-free-floating algae that forms the base of the food chain for aquatic animals. The study, published in the January 2007 issue of the journal Pesticide-Biochemistry and Physiology, indicates that protein levels in phytoplankton significantly decrease as a result of atrazine exposure, possibly having a negative affect on the nutritional levels of all aquatic species. The National Oceanic and Atmospheric Administration (NOAA) National Centers for Coastal Ocean Science researchers exposed five algal species to atrazine levels within the range of concentrations measured in the estuarine environment. In the majority of the species tested, the amount of energy converted into protein from photosynthesis, the process by which green plants convert water and carbon dioxide into organic materials using solar energy, significantly decreased with increased exposure. Atrazine is one of the most heavily used herbicides in the United States, applied to a wide variety of crops including corn, sorghum, sugarcane, pineapple, and Christmas trees, as well as turf. It acts as an inhibitor of photosynthesis by preventing the transfer of energy in certain plant species. NOAA researchers observed significant decreases in the size of […]
Posted in Water, Wildlife/Endangered Sp. | No Comments »
18
Jan
(Beyond Pesticides, January 18, 2007) A new study conducted in Costa Rica’s mountain forests indicates that surprisingly high concentrations of pesticides are accumulating far above the low altitudes at which they are used. Previously thought to be safe from pesticides applied to distant agricultural areas, some remote mountain forests of Costa Rica were found to have pesticide levels almost ten times greater than those in low-lying areas closer to farms and plantations. The study, led by University of Toronto, Scarborough professor Frank Wania, Ph.D., measured air and soil pesticide levels at 23 sites across Costa Rica in order to produce a model to predict potential accumulation of chemicals at high altitudes. The insecticide endosulfan and the fungicide chlorothalonil were found in the largest concentrations, with up to 1 part per billion (ppb) of chlorothalonil and 3 ppb endosulfan in soil. The high concentrations can be explained by a process in which polluted air above the farms and plantations is pushed up into the mountains, where it then cools and becomes polluted rainwater or fog. The hydrophilic nature of modern pesticides makes the occurrence of this phenomenon much more likely; as Crispin Halsall, Ph.D., of Lancaster University (U.K.) explains, “Most currently […]
Posted in Chemicals, Chlorothalonil, Endosulfan, International, Water, Wildlife/Endangered Sp. | No Comments »
