The “mystery illness” of Andhra Pradesh — now responsible for the death of an individual and more than 500 hospitalisations — is believed to be a mass neurotoxic poisoning due to heavy metal toxicity, according to an initial medical report.
As reported by Health Issues India as the situation unfolded, “the role of heavy metals such as lead and nickel are also being investigated for their role in the mysterious illness, after AIIMS [All India Institute of Medical Sciences] doctors found the metals in patients’ blood samples.”
On Saturday, December 5th, hundreds of residents of the city of Eluru in Andhra Pradesh rapidly fell ill with a range of symptoms that initially baffled experts. Symptoms of the mysterious illness include nausea, vomiting, severe headaches, loss of consciousness, anxiety, frothing, and seizures. A 45-year-old man died of epilepsy-type symptoms, currently the outbreak’s sole casualty at the time of writing.
“The sample size that we sent on an urgent basis to AIIMS was small but their report indicates presence of heavy metals like lead and nickel in the blood samples of patients,” superintendent of Eluru Government Hospital Dr A. V. Mohan told The Indian Express. “We have sent more samples and their reports are awaited.”
The source of the elevated levels of heavy metals in the blood samples of those affected has not yet been established. Initial speculation led experts to suspect potential contamination from pesticides used in the area, though this has not yet been confirmed.
“We have tentatively identified the primary cause of this strange phenomenon, but it is not yet clear what the source is and how and why it has happened,” said Katamaneni Bhaskar, a state health commissioner in Andhra Pradesh. “For instance, the chemicals were found in the bodies of the patients but not in either water or any other food substance.”
The residents of Eluru are reportedly blaming a recent anti-mosquito campaign. Organochlorine pesticides were used as part of the campaign to reduce mosquito populations in the area. Blame has been placed on the substance due to its capacity to cause severe neurological damage in humans if accidental high-level exposure occurs. In 2013, at least 25 children died in the state of Bihar after eating food that had been prepared in a cooking oil which contained high levels of the pesticide — which is as of yet unregulated within India.
Such large-scale outbreaks of heavy metal poisoning are not unprecedented in India. Many illnesses that occur in the country that have not been attributed a causative factor may also be explained by heavy metal poisoning according to AIIMS. Physicians at the facility tested 216 severely ill patients for whom there was no clear reason behind their ailment. Of these, 32 (14.8 percent) displayed concerningly high levels of pollutants ranging from arsenic to chromium to lead.
For many, an elevated level of heavy metals may be all but unavoidable as the very water the population drinks daily may be polluted in many areas. Groundwater in India is contaminated with high levels of uranium, found scientists of Duke University in the United States in 2018. Their findings showed that around a third of monitored locations contained uranium in much higher quantities than the World Health Organization’s (WHO) provisional standard of 30 µg/l for the country.
The presence of uranium is not unexpected and is a natural occurrence. Much of India’s water supply will have passed through the granitic rocks surrounding the Himalayas. These rocks are often rich in uranium.
Human influence may be enriching the water with enough uranium to drive the concentration to dangerous levels. Overpumping of groundwater can cause significant depletion of water levels. Depletion can, in turn, induce oxidation, which may lead to the reduced water supplies absorbing uranium particles from the surrounding rocks.
The same issue is caused by draughts, a problem to which India is no stranger. The frequency, as well as the severity of droughts, however, is worsening. With climate change expected to worsen over the coming years, India faces severe issues with rainfall shortage. The immediate effects of rainfall shortage are more apparent: drought, food shortages due to crop failure, and environmental degradation. However, long-term issues could be caused by greater concentrations of heavy metals seeping into ever depleting water reserves.
According to one monitoring platform, approximately 42 percent of the total land in India is prone to episodes of drought. This covers states home to 500 million Indians – almost forty percent of the total population. This affected area is only likely to expand, affecting a greater number of people over time.
The effect of droughts increasing concentrations of heavy metals in India’s water supply is, however, a long-term issue that may be difficult to address. More immediate issues, such as the regulation of insecticides known for causing neurological issues in individuals if entering the food system, could at the very least prevent acute breakouts of heavy metal poisoning.