Saturday, October 04, 2008 Oledan: Safety threats By Radzini Oledan Slice of Life
THE Talomo-Lipadas and Panigan-Tamugan watersheds are Davao City's groundwater recharge zone for shallow, deep and very deep aquifers, which make them the future source of drinking water for the populace.
But this potential is threatened by the presence of pesticide contaminants from banana and pineapple plantations, as shown by a study conducted by the Interface Development Interventions (IDIS) Inc. and the Ateneo de Davao University.
The study "Survey on the Level of Pesticide Contaminants Within the Talomo-Lipadas and Panigan-Tamugan Watersheds" covered the period November 2006-December 2007.
Pesticide contamination results from the use and/or misuse of agricultural pesticides, and is manifested as adverse effects on human health and the environment.
Pesticides are deliberately manufactured as poisons, albeit to destroy agricultural pests. By the same token, it also results in extensive damage to human health and the environment according to Department of Health Regional Director Dr. Paulyn Jean Rosell-Ubial.
The incidence of agricultural pesticide contamination or poisoning is exacerbated through misuse or unsafe use due to the absence of stringent regulations and the lack of enforcement of existing ones, including the importation of pesticides that have been banned or whose use are severely restricted in developed countries.
But despite the presence of huge agricultural plantations in the region, there is no capability to detect the level of toxicity as a result of agricultural pesticide contamination.
The study measured the levels of pesticides in water from 10 sampling stations. The pesticides that were monitored include those that are most commonly used by farmers and big banana and pineapple plantations such as paraquat, mancozeb, chlorpyrifos and diazinon. Samples were analyzed by the Bureau of Plant and Industry and Jefcor Laboratories.
Results of the study showed that pesticides used in crops within the watershed areas do end up in water and sediments. Eight of the 10 stations were positive for pesticide residue at least once during the survey period and usually when there is rain. Pesticides were commonly detected in stations 5, 6, 7, and 9, which receive surface run-off from at least one plantation known to be a heavy user of pesticides.
Six of the 13 pesticides detected are banned organochlorine pesticides.
Endosulfan, a strictly restricted pesticide that should not be used near aquatic ecosystem, was also detected from sediment samples. Two of the most commonly detected pesticides in water, namely chlorpyrifos and diazinon, were detected at levels higher than the United States Environment Protection Agency (US-EPA) regulatory limit for freshwater.
Dr. Lourdes Simpol, who led the research study, said that among the recommendations are the strict implementation of the provisions of the Water Code of the Philippines on easements where 20 meters on both sides of rivers/ streams in agricultural land be kept with vegetative cover, planted with trees, and clearly marked as permanent forest for stream or river bank protection.
The protection of the critical groundwater recharge zones will ensure the sustainability of our community and the viability of economic activities in the city.
