Heavy metals: Poison in our food

LAHORE:

Vegetables grown with water contaminated with industrial waste introduce heavy metals into the food chain and these have damaging effects on human health.

Tauqueer Qureshi, a chemical expert, says most tanneries and dyeing units in Pakistan still use chemical-based dyes. “These are carcinogenic and are retained in leafy vegetables. Zinc, cadmium, copper, lead and chromium are toxic heavy metals and largely make up the waste of tanneries. These are passed into grains and vegetables alike and then accumulate in human body. Their impact on human health is evident over long durations,” he said.

“Green fodder also retains carcinogens and is transmitted into the food cycle through meat and milk from cows, goats and buffaloes from this region.”

He said the long-term effects could be judged from the high proportion of cancer and kidney failure rates in Kasur, where people had long been exposed to waste from tanneries and textiles.

Qureshi said cucumber, raddish, spinach, cauliflower, cabbage and carrots retain more metals than other vegetables.

Gastroenterologist Dr Javed Akram told The Express Tribune that zinc and cadmium are retained by vegetables and grains more than other heavy metals. Consumption of contaminated vegetables and grains over a period of three to five years can cause kidney and liver failure, intestinal cancer and typhoid, he said.

Dr Akram said that bleaching agents used in dyeing and tanneries can hamper neurological growth in children and even cause retardation in children under five. They can also affect the blood vessels.

Published in The Express Tribune, October 6^th, 2012.