The study, published last month (November) in Science of the Total Environment, amassed hair samples from 22 sites in five zones in Pakistan — Swat Valley & Gilgit-Baltistan regions, Kashmir Valley, Lower Himalaya Mountains and Indus Plains.
The study which provides the first baseline data for total mercury contamination showed the heavy metal concentrated in agricultural and industrial areas in the lower Indus plains.
“Having analysed the data, we found that the highest mercury pollution of dust particles (3,000 particles per billion) and its bioaccumulation (2,480 ppb) were observed for the densely populated and highly industrialised Lahore district,” Syed Ali Musstjab Akber Shah Eqani, lead author of the study, tells SciDev.Net.
Scalp-hair was preferred for the sampling because it readily absorbs mercury and other trace metals from the environment, explains Hussain.
“Scalp-hair samples are cheaper and easier to collect as compared to nails, blood, and urine samples,” he says.
The researchers found industrial and hospital waste discharges as key sources of the mercury pollution in the surveyed areas. Mercury affects the nervous system, causes reproductive abnormalities, kidney failure, emotional instability, gingivitis and tremors or the shivering of body parts often initially with hands before spreading to other parts of the body. Mahmood Khwaja, senior advisor at the Sustainable Development Policy Institute (SDPI) in Islamabad, believes the gravity and scale of the country’s population’s exposure to the mercury risk remained largely unknown and with data gaps as a major roadblock to an effective policy response.
“The new baseline data (the mercury study) would plug the data gap and nudge the government into a policy action to cope with mercury toxicity,” Khwaja says.
Presently, an estimated 58 million of Pakistan’s 200 million people live in urban areas. By year 2030, around138 million people will be living in cities, according to a recent report of the Planning Commission of Pakistan.
Asif Shuja, former director general of Pakistan Environmental Protection Agency, warns that rapidly escalating urbanisation in the country could further aggravate risks to public health from mercury pollution, calling for timely policy responses.
This piece was produced by SciDev.Net’s Asia & Pacific desk.