in what place in asia or anywhere else in the world are tainted food in common observation?

Answer 1

Mexico has had some bad news reports through the years on shipping foods in the med west that have had some warnings on them. Foodstuffs like Strawberries, Melons and other fruits and vegetables. They have very poor standards down there.
Strawberries into Michigan and Wisconsin in about '86 caused many school children to become ill. Melons and other veggies in '06 caused E coli and other bacteria to enter

Answer 2

china. here's an excerpt of a wsj article:

China Shuts 180 Food Plants Amid Food-Safety Concerns

China has shut down 180 food factories after inspectors found industrial chemicals being used in an array of products. International concerns over China's food safety have ballooned this year.

Nicholas Zamiska, Wall Street Journal
June 27, 2007 1:29 p.m.

HONG KONG -- The Chinese government said that it has closed 180 food manufacturers found to have used industrial chemicals and additives in food products, acknowledging systematic problems in its food supply.

The acknowledgement, published Wednesday in a state-run newspaper, is the government's boldest admission of food-safety problems since a string of scandals involving tainted products made in China that have focused international attention and concern over the safety of Chinese exports.

"These are not isolated cases," Han Yi, director of the administration's quality control and inspection department, said at a press conference, according to a report in the state-run China Daily newspaper. He added that most of the manufacturers who had been shut down were small, unlicensed food plants with fewer than 10 employees.