Consumer Council says the levels in sardines and tuna pose no health threat Arsenic has been found in some types of tinned fish - but the Consumer Council says the levels detected are safe. The council found the heavy metal in samples of sardines packed in tomato sauce and in tuna packed in oil. Arsenic is the poison of choice for many murderers, in the real world and in fiction, most famously in the play and film Arsenic and Old Lace, in which a man finds that his maiden aunts are serial killers. But the levels of arsenic found in the fish are unlikely to harm anyone consuming moderate amounts. One expert said a person would have to eat at least nine large cans of the sardines a week to suffer any effect at all. The arsenic levels in the sardine samples ranged from 0.76 parts per million (ppm) to 2.34 ppm, while those in the tuna ranged from 0.79 ppm to 2.27 ppm. The amounts exceeded the mainland's limit of 0.5 ppm but were well within the Hong Kong's limit of 6.0 ppm. The tests also found mercury in four samples of canned tuna but the amount was below the mainland's and Hong Kong's standards. No samples contained lead. Arsenic in excessive quantities can harm the nervous and digestive systems. The Consumer Council said the detected levels were safe according to the standard set by the United Nations' and World Health Organisation's joint Expert Committee on Food Additives. The committee says a 60kg adult can safely consume no more than 0.9 milligrams of inorganic arsenic over seven days. The Consumer Council's vice-chairman of publicity and community relations, Ching Pak-chung, said one would have to eat at least nine large cans of sardines in a week to suffer any health risk. 'The amount is not threatening, unless you eat a lot every day,' he said. Arsenic occurs naturally in the water, air and ground. It can easily be absorbed by fish. 'The labels on the can tell you the origin of the fish, but it's hard to know the quality of the fish and whether it is contaminated,' Professor Ching said. The Food and Environmental Hygiene Department said there were no plans for a review of the regulations. 'There isn't a unified standard agreed by all countries, and since the amount of arsenic found in the products has not exceeded the limit set by Hong Kong, we don't see any urgency for a review,' a spokeswoman said.