KARACHI: Samples of chicken meat collected from various spots in the city have been found to have high levels of arsenic. The city’s environment hasn’t yet recovered from the damaging effects of leaded-gasoline that was phased out in 2001 and still the major (lead) source directly or indirectly contaminating food is leaded-petrol.
These are some important findings of a three-year research which was shared on Monday at a seminar held at the Aga Khan University (AKU).
Titled Heavy metals, food, safety and child development, the seminar was organised by a research group at the department of community health sciences (CHS) at the AKU. The study was conducted by the department in collaboration with the Jichi Medical University of Japan.
The study identified important sources of lead and arsenic exposure among newborns, children (aged between one and three years) and pregnant women in both countries. Its area of study in Pakistan were Karachi and Gambat (Khaipur).
Giving a presentation on the exposure of arsenic and lead through common food sources, Dr Abdul Ghani said the World Health Organisation (WHO) withdrew the Provisional Tolerable Weekly Intake (PTWI) for ingestion of lead and arsenic from all sources (25mcg per kilogram of bodyweight) in 2011 and hadn’t yet set revised safe limits.
There were no safe limits for lead and arsenic in food and ideally it should be free from these chemicals.
“In comparison with potato and lentils cooked in different types of utensils, poultry chicken meat contained 15 times higher concentration of arsenic (between 41ng/g and 47ng/g),” he said, suggesting that arsenic-based chicken feed and vaccines might be the source of contamination.
Asked if it’s safe to eat chicken meat contaminated with arsenic, he argued that since 40pc of children’s population suffered from severe malnutrition in the country and it’s the cheapest protein source for the public, the solution existed in eating chicken less, monitoring and regulating poultry farming and sale of chicken meat. “It’s not one time eating but frequent consumption of the same food that affects the body as metal traces accumulate in the body,” he explained.
Dr Zafar Fatmi, the principal investigator of the research, said the major source for lead exposure among pregnant women and newborns was found to be food followed by house-dust and respiratory dust.
“Lead from water and surma use was not found major contributors. The study also showed that the overall environment, including food, has the same isotopes as in petrol. This suggests that past exposure of lead from gasoline still affects the environment, although, the current level of lead in gasoline is according to the required standards,” he said.
According to the experts, there is no short-cut to get rid of the impact of leaded petrol and it will happen naturally over a course of time.
Highlighting the adverse impact of lead and arsenic on human body, he said both chemicals were of major public health concern since both elements had toxic effects that could cause irreversible neurological damage, especially in young children, and trigger a wide range of chronic diseases.
The women and children who took part in the study had blood lead levels significantly higher than the 5µg/dl (microgrammes per decilitre) used as a reference level for health risk by the US Centres for Disease Control and Prevention (CDC).
Sharing the study findings, Dr Ambreen Sahito said over 60 per cent of newborns and about 90 per cent of children had blood lead levels that exceeded CDC guidelines, a potential risk for lifelong health consequences.
Thirty-five percent of rural population had arsenic level more than the WHO recommended levels of 10mcg/I.
Animals and animal products such as meat, milk and milk products were found negatively associated with blood lead level. Blood lead levels were found higher in women eating rice regularly.
According to experts, exposure to lead can be limited by simple home activities, for instance, by maintaining hand hygiene and wet mopping.
Prof Asad Saeed from Karachi University, Seema Ashraf from the Pakistan Standards and Quality Control Authority and S.M. Yahya representing the Sindh Environmental Protection Agency also spoke.
Published in Dawn, December 6th, 2016