Common foods such as cabbage and salted or dried fish in the markets may contain dangerous amounts of pesticides and should be tested for consumer safety, some agriculture experts said.
The hazards of farmers misusing pesticides has long been an issue in Cambodia, where pesticides banned in many developed countries are still used. Sixty-two percent of farmers said they had experienced pesticide poisoning in a survey released this year by the Center for the Study of Agriculture Development of Cambodia.
But the effect on the consumer—while almost certainly less than the effect on the farmer—has gone virtually unstudied. It has worried Cedac Director Yang Saing Koma enough that he said he avoids all kinds of cabbage, which receives especially frequent sprayings.
“Pesticides affect everyone, not only the health of the farmer and the environment, but also the health of the consumer in the city,” he said.
Cabbage is not an ideal hot-weather crop, so farmers aid its growth through heavy use of nitrogen fertilizers, which attracts more insects, he said.
Bruce Todd, a chemist and technical fisheries adviser with Oxfam America, said he was alarmed to learn that Cambodians frequently spray their dried and salted fish with pesticides to keep pests away at the market.
“It would boggle my mind if this turned out to be a safe practice,” he said.
The most common pesticides sprayed on fish are dichlorvos and mevinphos, both classified by the World Health Organization as extremely or highly hazardous, Todd said. Those and other so-called Class 1 chemicals were banned by the Cambodian government in 1998. They are dangerous when inhaled or absorbed through the skin.
In most developed countries, users of Class 1 pesticides must be licensed and trained in safe handling practices. But Todd said he watched family-business fish processors spraying the pesticides without even wearing rubber gloves. Most of the pesticides are imported and come with warning labels in foreign languages that Cambodians cannot read, he said.
Mevinphos, dichlorvos and methylparathion, a common crop pesticide, are so-called organophosphates, or neurotoxins. Their acute effects include diarrhea and vomiting. Other pesticides such as DDT are carcinogens that accumulate slowly in fat.
Neither fish nor vegetables have been tested in Phnom Penh markets, experts said, so no firm conclusions can be reached on their safety. But vegetables are likely being harvested and consumed faster than their toxic effects can wear off.
Agriculture extension guidelines recommend that vegetables sprayed with methylparathion stay in the field for at least 15 days before harvesting, to allow the toxins to decompose into harmless elements, Yang Saing Koma said.
But it’s common for farmers using methylparathion to “spray today and harvest tomorrow. They say if you wait too long, pests can come,” Yang Saing Koma said.
Robert Nugent, country officer for the UN Food and Agriculture Organization, said it was “likely vegetables at the market have been sprayed within the last 24 hours, probably with methylparathion.”
Some kinds of pesticides may succeed in entering the flesh of fish and fruit, Yang Saing Koma said. He recommended that consumers be familiar with vendors so they “know the origin” of fish bought at markets.
Nonetheless, Nugent said this knowledge has had little effect on his own dietary habits. Organophosphates can be neutralized by washing or cooking, he said.
“This is no reason to go to an all-meat diet. There are far greater health risks in Phnom Penh,” he said.