Continued from page 1

Some countries, such as Thailand, are trying to improve domestic food safety. In bustling Bangkok, where pots bubble and woks sizzle at makeshift kitchens set up on sidewalks, markets are issued test kits that can detect up to 22 contaminants.

No one knows the extent of chemical-laced food in Asia or how it will affect public health.

“It might be that you consume it today, but you don’t see any effects for 10 years,” said Peter Sousa Hoejskov, a food quality and safety officer at the U.N. Food and Agriculture Organization in Thailand. “Some foods have issues that are developing over a long, long time and others you have an immediate reaction.”

China has faced outrage among its own citizens in recent years. Whiskey laced with methanol, a toxic wood alcohol, was blamed for killing at least 11 persons in southern Guangzhou. Local news media in Shanghai uncovered the sale of phony tofu made from gypsum, paint and starch.

At least a dozen Chinese babies died and more than 200 were sickened with symptoms associated with malnutrition after drinking infant formula made of sugar and starch with few nutrients. In another case, lard for human consumption was made with hog slop, sewage, pesticides and recycled industrial oil.

Some Vietnamese have been so shaken by news of tainted Chinese foods, they are changing their eating habits. They are avoiding Chinese-made products and paying more — up to $2 a bowl — for pho at an air-conditioned chain restaurant with signs promising no formaldehyde or borax.

“I am very, very worried about it,” said Duong Thuy Quynh, 31, who was eating beef pho because she was also worried about bird flu in chicken. “I’m ready to pay more to protect myself and my family.”