Contaminated vegetables pose serious threat to KP people

PESHAWAR: A government report has revealed that contaminated vegetables have become a serious threat to human health in six districts of Khyber Pakhtunkhwa.

The report prepared by the Khyber Pakhtunkhwa Department of Agriculture and Livestock has shown evidence of heavy metal contamination of one or more elements in soil, water, and vegetables irrigated by industrial pollution and wastewater in six major districts of Khyber Pakhtunkhwa. These metals accumulated from industrial effluents, hospital waste and domestic wastewater has prone serious threats to human health.

The report has also revealed that the toxic elements are non-degradable, long biological half-life, less visible, not metabolised, and can cause severe disorders of cardiovascular diseases, cancer, and cognitive impairment, and anemia, damage to kidneys, nervous system, brain, skin, and bones. The most contaminated vegetable samples with respect to heavy metals were found in Peshawar followed by Abbottabad, D.I. Khan, Mardan, Mansehra and Charsadda.The Directorate of Soil and Plant Nutrition Soil Chemistry Section of Agriculture and Livestock Department, Khyber Pakhtunkhwa, has carried out the research and analysed the samples through international standard protocols to determine the level and extent of heavy metals in irrigation water, soil and vegetables grown on contaminated sites in the big cities of the province. The long-term use of such contaminated water accumulates heavy metals in toxic concentrations in the soil and then transports them to humans through crops.

Provincial Minister for Agriculture Muhibullah Khan told this scribe that the provincial government has taken encouraging steps in this regard. The research was started in 2019, which was completed and submitted to the government in the light of which the measures have been finalised.

The government has approved the ADP project, which focuses on research as stabilisation of heavy metals through the construction of Bioremediation structure (a low cost, non-destructive, and environmentally friendly approach) at the Agriculture Research Institute, Tarnab, Peshawar, along with strengthening of labs for assessment of fertiliser and pesticide adulteration.

The government also issued directives to the district administration to stop the soil irrigation with polluted water and make necessary arrangements for a separate sewerage system to dispose of the polluted water.

The report, presented by Muhammad Rashid, Senior Research Officer, said the Khyber Pakhtunkhwa has very low or limited wastewater treatment facilities. Most of the existing water treatment plants did not work properly or were converted for commercial purposes in many places. Also, the absence of technical and financial resources makes it very difficult to efficiently collect and treat waste water, he added.

Industrial effluents, hospital waste and domestic utilities release untreated waste in nearby rivers and streams. The approximate area irrigated through waste water in the s x districts, except DI Khan, is 8,142 ha.

This wastewater pollutes the soil with heavy metals and hence the vegetable and crops grown on these soils have become a serious health threat to the consumers. The report said the samples were collected from Peshawar, Charsadda, Mardan, Abbottabad, Mansehra and DI Khan, the industrial hub and fastest-growing cities of the province. In these areas, many factories release wastewater in addition to the sewerage water into nearby irrigation channels and canals, and vegetables cultivated with this water could be a major food chain route of heavy metals for human exposure.

The overall contamination of heavy metals in irrigation water of all the districts follows the pattern Cd, Pb, Ni, and Cr. In the soils of all the selected districts, there is a hazard of Cd, Cr, and Pb in most of the districts.

The vegetable samples from all the districts are almost 100 pc contaminated with Cd followed by Cr, Ni, and Pb. The most contaminated vegetable samples with respect to heavy metals were found in Peshawar followed by Abbottabad, DI Khan, Mardan, Mansehra and Charsadda.

In Peshawar, all the vegetable samples have Cd and Ni contents above safe limits, while Zn, Cu, and Pb were found higher in 88, 48, 36 pc samples, respectively. The percent contaminations of heavy metals in vegetable samples of District Mardan, above safe limits, were 100, 9, 37, and 37 pc for Cd, Zn, Ni, and Pb, while in District Abbottabad 67, 50, 67, 25, 33 pc vegetable samples were found above permissible limits for Cd, Zn, Ni, Cu, and Pb, respectively. Sources of some common trace elements include mining byproducts, smelting of Zn, Cu, and lead, pesticides, chemical wastes, paints, and wood preservatives Cr-Metal plating, cooling tower water, additives (pigments and food preservative), electronics, industrial (paints, paper, rubber, cement, and leather) Cd-Industrial discharge, mining wastes, metal plating, water pipes, plastics and paints, batteries, sewage sludge, fossil fuel combustion, polymer stabilisers, impurities in fertilisers. Pb-Industry, cable covering, mining, plumbing, ammunition, PVC pipes, pencils, x-ray shielding, coal, gasoline, fertilizers, and pesticides.

The Ni-Industries, alloy manufacture, electroplating, sewage sludge, Cu-Metal plating, industrial and domestic wastes, mining and minerals leaching, fertilizers and pesticides.