KARACHI, April 24 People hooked on supari (areca nut), gutka, paan masala,mainpuri and tobacco are exposed to a wide range of diseases caused by a high level of trace and toxic metals found in all these chewable products, a Pakistan Council of Scientific and Industrial Research study has found.

Around 200 samples were collected from across the metropolis and examined for the three-year research conducted by the Centre of Environmental Studies, PCSIR.

The first-ever detailed study in the country analysed the chewable products and determined the concentration of trace and toxic metals in supari (63 samples), gutka (over 100 samples), tobacco (16), mainpuri (four samples) and paan masala (21 samples).

“We have analysed 12 metals — nine trace metals [of them four essential trace metals] and three toxic metals. The traces of toxic metals such as lead and cadmium were found in all the chewing products tested for the purpose. Toxic metals carry serious health risks as they can accumulate in the body and in the food chain,” Farooq Ahmed Khan, a senior scientific officer at the PCSIR, who along with scientific officers Mohammad Tahir and Akhtar Sharif completed the three-year research on metal poisoning, told Dawn.

Mr Khan said “Considering the fact that the human body is already exposed to a number of metal contaminants and pollutants, this study underscores the need for looking into the accumulative effect of these metals on human body in the long run.”

The study not only shows contamination level of different metals in a single brand, but also the minimum and maximum daily intake of these metals.

“It is necessary to know daily intake of metals because we know that a majority of people who are hooked on areca nut and its various concoctions consume them in large quantities every day. If we had only highlighted the concentration of metals in a single dose that has been found to be within limits in most cases, a public awareness message based on these statistics would have failed,” said Mr Tahir.

The maximum to minimum intake of metals has been based on another research according to which generally 10 to 15 packets of areca nut and gutka are consumed on a daily basis.

Findings

According to the research findings, the minimum to maximum per day range of metals found in gutka was as follows lead (0.6mg/day to 40mg/day), nickel (6mg/day to 31mg/day), cadmium (0.2mg/day to 2mg/day), iron (19mg/day to 23mg/day), chromium (39mg/day-56mg/day), manganese (4mg/day-7.5mg/day), zinc (19mg/day to 21.8mg/day) and copper (690mg/day to 750mg/day).

The minimum to maximum per day range of metals found in areca nut was lead (0.6-72mg/day), nickel (1.6mg/day to 87mg/day), cadmium (0.54 to 3.4mg/day), iron (0.1mg/day to 6.5mg/day), chromium (0.01mg/day to 21mg/day), manganese (0.2mg/day to 1.8mg/day), zinc (0.06mg/day to 26mg/day) and copper (0.02mg/day to 0.7mg/day).

The minimum to maximum range of metals in tobacco was Iron (17mg/day to 23.67), copper (800mg/day-1060mg/day), manganese (4mg/day-7mg/day), zinc (11mg/day-13mg/day), chromium (41mg/day to 60mg/day).

The traces of lead, cadmium and nickel were also found in tobacco.

Adverse impact on health

Dr Aliya Munshi, who heads the Centre of Environmental Studies, said that both trace and toxic metals had adverse impact on health. She explained that essential trace metals such as zinc, copper, manganese and iron, if taken in large quantities, became toxic and caused serious health hazards. Similarly, toxic metals might get deposited in human body and caused long-term ill-effects on health, she added.

“Toxic metals can directly or indirectly damage the DNA, which increases the risk of cancer. Heavy metals disrupt metabolic functions in two ways firstly they accumulate and disrupt function in vital organs and glands and secondly they displace the nutritional minerals vital for biological function.”

She explained “Although they can be found in high concentrations in the body, a number of heavy metals (aluminum, beryllium, cadmium, lead and mercury) have no known biological functions. Others (arsenic, copper, iron and nickel) are thought to be essential at low concentrations, but are toxic at high levels.

“Toxic metals can't fulfil the same role as the nutritional minerals, thus their presence becomes critically disruptive to enzyme activity. The usual target is the lung, though arsenic has a unique association with skin cancers and that has been recognised for many years.”

According to Dr Munshi, the gradual accumulation of toxic and trace metals in human body results in slow poisoning. The traces of lead, cadmium and chromium can also be passed on to newborns through the placenta, she said.

Regarding the sources of metal contamination in chewable products, she said that it would require another study to determine the exact source causing contamination of a specific metal in the case. However, polluted water and soil were two major sources for any contamination.

Oral cancer epidemic

It is also important to mention here that a number of studies have attributed the incidence of head and neck cancers to consumption of betel leaf (paan), areca nut (chalia), tobacco and their various concoctions such as gutka and mainpuri.

Recent studies on the subject show that Karachi has the highest incidence of oral cancer in the world. With the increasing number of oral cancer cases, the city may witness an epidemic in the coming years, medical experts believe.

A study conducted by the sociology department of Karachi University in 2006 found that 93 per cent children of 50 government and private schools in Saddar Town spent their pocket money on buying areca nut and seven per cent on betel leaf (paan) and gutka.

An Aga Khan University research titled, Socio-demographic correlates of betel, areca and smokeless tobacco use as high risk behaviour for head and neck cancers in a squatter settlement of Karachi, found that head and neck cancers were a major cancer burden in Pakistan.“They share a common risk factor profile, including regular consumption of products of betel, areca and tobacco. Use of paan, chhaalia, gutka, niswar and tobacco is acceptable in Pakistan and is considered a normal cultural practice.”

Regarding the increasing use of these chewable products among children, the research report stated that it would have dire consequences on public health as a time-trend analysis of oral cavity cancer in Karachi had already reported up to 200 per cent increase in cases among lower socio-economic strata between 1998 and 2002.