KARACHI: A study recently conducted by a team of Karachi University (KU) researchers showed that the ice being used to make different food items is heavily contaminated, particularly with some toxic, cancer-causing metals, and not fit for human consumption. The research was carried out at the KU’s Institute Environmental Studies (IES).

The team collected 42 samples from all the six districts of Karachi and conducted analysis of different physicochemical parameters and heavy metals to check their quality.

According to the findings, all the ice samples were grossly contaminated with arsenic and lead and crossed the 0.01 mg/L limit set by the WHO. The maximum lead content (5.71 mg/L) was observed in the sample collected from Jamia Milia, Malir.

All samples failed to meet the 2011 WHO guidelines on nickel. The highest nickel level (2.55 mg/L) was observed in Muslimabad, Landhi. As many as 21.4 per cent samples had values greater than 1mg/L. The maximum allowable WHO limit set for nickel is 0.07mg/L.

<‘Long term exposure to toxic metals poses serious health risks’

The value of chromium fluctuated between 0.055mg/L and 0.93mg/L against the WHO value of 0.050.93mg/L.

A total of 28.57 per cent samples had sulphate levels above the WHO guidelines of 250 mg/L. The maximum sulphate concentration of 432mg/L was observed at Anda Mor in North Karachi.

The mean chloride value was found to be 96.271 mg/L.

Two ice samples collected from Gadap town and Shadman Town crossed the WHO guidelines (250 mg/L).

The minimum and maximum TDS (total dissolved solids) value was 512mg/L and 2451mg/L, which was found in the sample collected from Shadman Town. The WHO 2011 guidelines say that water TDS should be less than 1000 mg/L.

Chloride in water, according to the study, is considered to be safe at low concentration, but it could alter water taste at a concentration of above 250 mg/L.

Only two ice samples collected from Gadap Town and Shadman crossed the guidelines (250 mg/L).

A number of samples had hardness greater than 500mg/L set by the WHO. These samples were collected from Madras Chowk, Orangi Town 13, Gadap, Shadman Town and North Karachi.

Water hardness greater than 500 mg/L, the study says, would have adverse health effects on human health and may cause kidney stone formation and cardiovascular diseases.

The maximum hardness level was observed in Gadap town with a concentration of 1040mg/L.

All ice samples, however, had nitrate levels within the maximum allowable limit of 50 mg/L set by the WHO.

The team led by Dr Aamir Alamgir, assistant professor at IES, included Noor Fatima and Qamar Ali.

Contaminated water

According to Dr Alamgir, it’s the first detailed study on the quality of ice being commonly used in cold drinks, juices, milkshakes, ice-creams and ice lollies, among other food items.

The study’s findings, he pointed out, endorsed findings of past studies that had reported higher levels of toxic metals in both piped and tanker water in the city.

“Higher levels of toxic metals, such as lead, arsenic and chromium, in samples clearly indicate that the water being used for making ice is contaminated with untreated industrial effluents,” he said, adding that chromium was widely used in industries such as glass manufacturing, electroplating, dyes and paint, tannery, chemicals and steel alloy.

Call for action

A change in water taste, he said, was an indication of high TDS level in water.

“Studies show that the long term use/exposure to toxic metals poses serious health risks. For instance, the use of arsenic contaminated water even in low levels might cause diabetes, lung and heart diseases, cancer and disruption in cell communication. High levels of sulphate are responsible for gastrointestinal impatience and dehydration.”

Expressing concern on the study’s findings, Dr Abdul Ghafoor Shoro, a senior general physician associated with Pakistan Medical Association, said international studies had revealed that 60pc of the diseases were caused by polluted water, but this risk increased multiple times if the water was contaminated with toxic metals.

“We have been seeing a constant rise in several diseases, such as cancer, over the years. This situation seems to be linked with environmental factors, including the use of contaminated water and polluted air, as the provincial government has failed miserably to deliver and there are no regulatory quality checks on the food being sold in the market.”

The study, he said, should serve as a wake-up call for the government, which could effectively reduce spending on the primary healthcare services only if it provided clean and safe drinking water to the masses.

“We know where all the allocated health funds go. It’s time that the government take up its basic responsibility and that is to provide clean drinking water and sanitation services to the general public,” he said.

Published in Dawn, July 25th, 2022