Kochi: Chief Minister Pinarayi Vijayan on Wednesday announced in the Assembly that a scientific study would be conducted by experts to find out if the massive fire and smoke at Brahmapuram waste dump yard have left residues that can cause long-term health issues in the soil, water or even people of Kochi.

The chief minister's announcement comes amid a clarion call by activists and scientist community for such a study as they fear the fire and resultant smoke troubled the region for at least 12 days. The Kerala State Pollution Control Board, which has been critical of the way the waste dump yard – a miserably failed solid waste treatment plant – functions, has also decided to send samples of air, water and soil of Brahmapuram for tests.

It is not clear when these proposed tests would be conducted and how long one should wait for the results. Studies from the past, meanwhile, have raised enough red flags that should worry Kochi. However, what one should be more bothered about is the fact that not enough studies have been conducted to assess the real impact of the summer fires at Brahmapuram yet.

The authentic studies available on the impact of the open burning of municipal solid wastes at Brahmapuram are the ones conducted by the Environmental Technology Division of the Council of Scientific & Industrial Research - National Institute for Interdisciplinary Science & Technology (CSIR - NIIST), Thiruvananthapuram following the fire breakouts at the plant in 2019 and 2020. While the national institute conducted the first study voluntarily, the second was done at the initiative of Justice A V Ramakrishna Pillai, the then chairman of the State Level Monitoring Committee, an authority constituted by the National Green Tribunal. Both the studies had found that the dioxin emissions caused by the fire breakouts were higher than the control level.

Dioxins is the general term to represent three groups of unintentionally produced persistent organic pollutant (U-POPs) – polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like Polychlorinated biphenyls (dl- PCBs). “Dioxins are highly persistent, bio-accumulative and toxic organochlorine compounds which are classified as known carcinogens (Type A) by World Health Organization (WHO). These toxicants are reported to persist inside human body for about 7-12 years due to its lipophilicity and are known to cause mutagenic and teratogenic effects,” the 2020 report says.

One of the major findings of the study in 2020 is that “the average dioxin levels observed in the ambient air was found to be 3.2 pg TEQ/m3 of air, which is 2.5 and 16 times higher than field blank and control site measurements respectively.” What is to be noted here is that the fire lasted only for three days – from February 18 to 20 – in 2020 while the blaze and the fumes were alive for 12 days this time. Hence, it is rightly presumed that the volume of pollution caused by the recent fire could be manifold compared to the previous incidents. So could be the threats posed by it.

The study based on the tests conducted on air and soil/ash samples from the site, has estimated the incremental lifetime cancer risk. “(The study) found that the risk factor at the site is above the action level of 1×10−6 . This indicates a low level of cancer risk persists at the site due to the PCDD/Fs emissions from accidental MSW open fires,” the study report states. Then comes what sounds like a warning – “95-97% of dioxins exposure to humans occurs through ingestion pathway (through food) and only 3-5% occurs through inhalation and dermal pathways. As ingestion route was not assessed in the present study the risk factors at the site is expected to be higher than that estimated in the current report.”

Risks from dioxins occur through inhalation, dermal exposure and ingestion. The ingestion exposure which is the most dangerous occurs through intake of contaminated food. In order to assess the risk, food samples like crops cultivated and milk and eggs collected from the affected area have to be tested. It had not been done during the previous incidents at Brahmapuram. It is also not clear if the authorities have any plan to carry out the most relevant study this time.

The CSIR, in its 2019 and 2020 reports, had strongly recommended the need for a study on dietary exposure. Nothing took place, though.

“An extremely important aspect to be addressed is the assessment of ingestion exposure via food chain, which was recommended in the 2019 report as well. More than 90 % of human exposure to dioxins and furans occurs via food chain especially through animal origin food samples due to the highly lipophilic nature of these contaminants. The decade-old history of fire breakout incidents must have resulted in the contamination of nearby vegetation and human settlement areas. It will definitely result in exposure to the free ranging hens, cows and any other animals grazing in the area and also to the fishes in the nearby streams or ponds. Human exposure mainly occurs through the consumption of bio-magnified animal origin products such as eggs, milk, fish, meat etc. A systematic study of the levels of dioxins in animal origin food samples from the surrounding region is highly recommended to predict the health risk of consumption,” the 2020 report states.

It is learnt from top sources that the CSIR-NIIST could not carry out the tests despite having expertise and accreditation for analysis of dioxins and furans in food and feed samples because of the higher costs involved. The institute should be ready to conduct the tests if there’s some necessary funding for that. The CSIR-NIIST has been engaged by the State Pollution Control Board to conduct a study on Brahmapuram this time too and they have collected samples of air and ashes from the area. It will take three-four months for the results of the studies to be out. The results, unfortunately, will remain incomplete again, if there is no concrete initiative to assess the food samples also.