Was it pesticide poisoning? Was it heavy metals contamination? Or a combination of both? The sudden, mini-epidemic that saw around 600 confirmed cases with one reported fatality in Eluru, an agriculture rich town of Andhra Pradesh in the first half of December, initially baffled many.

With hundreds pouring into hospitals within days, alarm bells were set off. The unexpected spurt was labelled as a “mystery illness” and caught national attention.

The Andhra Pradesh government constituted a multi-disciplinary, 21 member, expert panel from institutions such as the All India Institute of Medical Sciences, Centre for Cellular and Molecular Biology, Indian Institute of Chemical Technology, the National Institute of Nutrition, the National Institute of Virology, the National Environmental Engineering Research Institute and others to investigate the situation.

This, at a time when the Covid-19 pandemic was already ongoing. A stressed, inadequate government health infrastructure in the form of medium-sized hospitals managed to contain the agony of the victims within their means.

The affected, men, women, young and old, typically exhibited symptoms like vomiting, severe headache, dizziness, anxiety, epileptic seizures etc. The numbers did not mount further and the impact seemed restricted geographically to a few colonies in Eluru town in West Godavari district.

Patients at Government General Hospital at Eluru in West Godavari district of Andhra Pradesh. Photo credit: Ch Vijaya Bhaskar

The first report by the expert group submitted to the Andhra Pradesh government and contents announced by Chief Minister Y S Jaganmohan Reddy pointed to pesticide residues and heavy metal contamination as the main reasons. However, it was not clear to the investigation how the pesticide residues or heavy metal contamination reached the food chain and the human bodies.

The pesticide residues like organochlorines and traces of nickel and lead were found in blood samples of several patients. The government and investigators decided further study to establish the link and the exact cause for the outbreak.

Long term deterioration

Eluru is the headquarters of West Godavari district and is one of the 13 districts in the state of Andhra Pradesh. With a population of about 40 lakhs, the district is bound by Krishna district on the west, East Godavari District on the east, Bay of Bengal on the south and the state of Telangana on the north.

Intensive agriculture, the growth of aquaculture and the agri processing industry, over the past three decades to four decades, have seen the largescale use of a variety of agrochemicals and pesticides in coastal districts of Andhra Pradesh.

The Krishna and East and West Godavari districts are very fertile lands and highly irrigated. Eluru lies in the lower region of the Krishna-Godavari Delta region.

Experts from Nagarjuna University in Guntur point out that since it’s a low lying area, the chemicals that are applied in the upland region (especially Krishna and Khammam) get washed all over the place.

The best example to illustrate this phenomenon is the well known Kolleru lake, about 15 km from Eluru. The once expansive wetland stretching to about 245 sq km has shrunk in size and turned into a “sink of pollutants”. The pesticides flowed and accumulated over the decades.

Aquaculture (over a 1000 fish ponds) occupies nearly 40% area. In addition, the construction has also taken a toll. Consequently, though a globally protected wetland under the Ramsar Convention, Kolleru flow reduced in size and is shorn of its famous Siberian Cranes.

In a letter to the chief minister, K Veeraiah, professor and dean, Faculty of Natural Sciences and Department of Zoology and Aquaculture pointed out that pesticide residues, especially, organochlorine, organophosphate, carbamate are quite common in the region and foods.

“Our own studies way back in 1996 reported about the presence of organochlorine pesticide residues,” Veeraiah said. “There are several other reports on the presence of these pesticides in this region too.”

Referring to the present episode, he stated in the letter that the sudden public health condition could be due to the influx of heavy metals from the opencast mining at Sathupalli of neighbouring Khammam district. Heavy metals are long-lasting in the environment and even in the organisms.

There is also speculation that the recent heavy rains and floods (August-September) in that region could have caused washing of these mining wastes into the river Thammileru which runs through Khammam, Krishna and West Godavari districts. Most of the mining wastes contain heavy metals like lead, nickel, copper, mercury and cadmium. The present reports have already revealed some of these residues in samples.

Multiple findings

The first indications of the epidemic came towards the middle of November. District officials said cases were reported but were few and treated in private hospitals. Up to December 4, about 20 cases came to light, but since they were random and spread out and treated, no suspicion arose, according to Mutyala Raju the District Collector.

Each of the institutes with their own expertise gave preliminary reports. According to the AIIMS, which has a Centre in Mangalagiri near Vijayawada, lead was detected in blood samples of around 30 individuals. Nickel, another potentially toxic chemical, was found in milk samples taken from patients’ houses. Preliminary tests also showed lead in blood samples of patients’ family members.

On the other hand the Indian Institute of Chemical Technology, Hyderabad experts found no trace of heavy metals – lead, nickel or arsenic or pesticide residues in 21 drinking water samples. However, endosulfan (an organochlorine insecticide) and DDT (another harmful pesticide) were found in blood samples. Lead was also found but no trace of organophosphates were present, they said.

Hyderabad’s National Institute of Nutrition reported pesticide residue in tomato and brinjal samples. Tests by the Centre for Cellular and Molecular Biology in Hyderabad and the National Institute of Virology in Pune found no evidence of bacterial or viral infection.

Pesticide residues and heavy metal contamination were first reported as the main reasons for the illness outbreak in Eluru in December. Photo credit: Ch Vijaya Bhaskar

Tests on air quality by the National Environmental Engineering Research Institute in Hyderabad found pollution within permissible limits. The institute also tested underground water and surface water samples and found all metals to be within permissible limits, except for mercury. Tests showed levels of mercury to be higher in underground water samples than those from surface sources.

Rice bowl and pesticide use

For decades, the coastal districts, especially the Krishna- Godavari districts of Andhra Pradesh were popular as the “rice bowl” of India. With abundant water, farmers grew fine varieties of paddy in the Delta region. Eluru town, situated at the gradient, flourished.

However, the availability of pesticides and chemicals attracted the farmers to use them to push up productivity. In no time, the move did yield good results, both for the farmers and the manufacturers. But, the flip side was to manifest soon. Guntur, emerged as the “pesticide capital”, with all major brands having their operations there.

In a couple of decades, the use of pesticides both branded and many local variants (misbranded) rose to excess levels. At the same time, the traditional farming practices too changed with some taking up aquaculture, prawn culture etc which would be more commercially viable. While commerce flourished, the environment seems to have taken a beating say researchers from the Acharya Nagarjuna University in Guntur.

The large-scale use of pesticides and chemicals for agriculture and aquaculture and the discharge of the wastes into water bodies as been a common practice in the region for decades. Several banned and environmentally harmful ones too, like DDT (banned in some countries) too have been used.

In addition, there are more than two dozen large aquaculture units, which are engaged in the aquaculture export business in Eluru. Roughly 10,000 tonnes of fish and prawn catch is processed, packaged and exported to various countries.

Way forward

While there is some respite in the fact that cases did not rise beyond a certain point, it is a warning on the environment and pollution levels in the region. The experts too suggested tracking food samples, water and plant and fish for a couple of months to see if the pollutants have entered the food chain.

The chief minister announced a follow-up action that included cracking down on dumping grounds and regular testing of food, soil and water samples. The state agriculture department was told to withdraw harmful pesticides and encourage farmers to opt for organic alternatives.

This article first appeared on Mongabay.