Dust in areas surrounding pesticide manufacturing units and farmland in Lahore contains harmful levels of pesticide pollution, a study done jointly by researchers at Quaid-e-Azam University and Lancaster University has found.
Farmers, factory workers and residents of such areas are exposed to harmful effects of these pesticides, particularly related to the nervous and endocrine systems. The areas studied by the researchers were Sundar and Quaid-e-Azam industrial estates, and neighbourhoods in Kot Lakhpat and Thokar Niaz Baig, and along Ferozepur Road, Multan Road, Kacha Jail Road, and Kalar Bund Road.
Researchers evaluated concentration levels of seven pesticide compounds, including organophosphates like chlorpyrifos and diazinon, in dust samples collected from these areas. Researchers then studied blood and urine samples from more than 500 men aged between 20 and 55. These men were selected from among farmers and workers at pesticide factories and from residential areas. Finally, the results from these samples were compared to those taken from a control group of 50 men selected from various districts in northern areas of the country.
“The most prominent pesticide components found in blood samples were chlorpyrifos and diazinon, which have been outlawed for residential use in the United States. It can affect humans through inhalation, ingestion or through absorption from the skin,” says a report published on the research by the Lancaster University.
Urine samples were found to be contaminated with high levels of biomarkers associated with chlorpyrifos and diazinon. “Biomarkers in blood samples also suggest that oxidative stress was experienced by all subjects when compared to the control group. Although not a conclusive link, a known risk of exposure to insecticides is disturbance to the antioxidant defence system,” the report says.
The blood and urine samples studied by the researchers were also found to have lower levels of an important enzyme needed for the nervous system.
Dr Crispin Halsall, a reader at Lancaster Environment Centre and co-author of the study, has been quoted in the report as saying, “The high levels of the indicators show that in Lahore, dust dispersing from industrial sites and farms is a major contributor to human insecticide exposure – in addition to pesticides found on food.”
He said that the manufacture and overuse of pesticides like chlorpyrifos and diazinon posed serious health risks.
Dr Riffat Naseem Malik, a co-author of the study, has been quoted as saying, “We need to further evaluate and weigh benefits of these pesticides against their deleterious effects on environment and human health, before it’s too late.”
The Lancaster University report states that Pakistan is the second biggest consumer of pesticides in South Asia. It highlights that globally, around 200,000 people die each year in developing countries due to organophosphorus pesticide poisoning.
The study has been published under the title ‘Pesticides contaminated dust exposure, risk diagnosis and exposure markers in occupational and residential settings of Lahore, Pakistan’ in the journal of Environmental Toxicology and Pharmacology.
Besides Dr Halsall and Riffat Nasreen Malik, the research team included Sidra Waheed from Quaid-i-Azam University, and Andrew Sweetman and Kevin Jones from Lancaster University.