Whenever farmworker Sonali Kadam experiences pain in her lower abdomen, she fears losing consciousness and pops a painkiller. 

Her fearful response goes back a decade when she was diagnosed with nephrolithiasis, commonly known as kidney stones, which are hard deposits of salt and minerals formed in the kidneys. 

When Kadam, a farmworker, first experienced this pain, she ignored it and kept working in the sugarcane fields. Within an hour, her pain aggravated, and she collapsed. 

Kadam, a resident of Arjunwad village in India’s Maharashtra state, has multiple stones in the kidney, each around 8mm in size. Usually, stones smaller than 5mm pass on their own through urine, while bigger stones might need medical intervention and sometimes even surgery.

In her quest to get rid of these stones, Kadam has consulted over 10 different doctors and took hundreds of painkillers but nothing worked. 

“This has traumatized me so much that whenever it starts paining, I fear I will either faint or die,” she told Health Policy Watch.

Kadam, 34, says her condition worsens in summers when the temperature tops 40° Celsius. As a farmworker, her day in the fields begins at 9am. There she sows seeds, clears weeds and harvests crops until about 5.30pm each day. 

“During this time, I am exposed to a lot of heat, which has been worsening my kidney stones,” she shares

Kidney disease rises with temperature

What Kadam has experienced isn’t a one-off case. Higher temperatures cause dehydration, leading to a rising concentration of minerals like calcium in the urine, which is responsible for the growth of kidney stones. 

A study published in the Lancet in March 2024 analyzed 135,4675 Acute Kidney Injury (AKI) cases in England between 2017 and 2021 and found a 62.3% increased odds of AKI when temperatures reached 32°C compared with that at 17°C. The researchers also found that in July 2021, a week-long heatwave led to a 28.6% increase in AKI counts. 

A study by the Children’s Hospital of Philadelphia in 2014 analyzed over 60,000 US patients and found a rising probability of people being diagnosed with kidney stones as daily temperatures rose. Researchers found that, at 30° C, the relative risk of kidney stone presentation was 36-39% higher than at 10° C.

Research from Australia points out that even a 1°C rise in daily minimum temperature increased emergency department admissions for kidney stones. 

Meanwhile, a paper in Nature’s Scientific Reports in January 2022 projecting the impact of rising heat on kidney stones in South Carolina, predicts that by 2089, even in the case of aggressive reduction in greenhouse gas emissions, the prevalence of kidney stones will increase by between 2.2% and 3.9%, costing an additional $57 million to $99 million respectively..  

According to the Global Burden of Disease study, 116 million cases of acute urolithiasis, a condition in which kidney stones move into the ureters, urethra, and bladder from the renal pelvis, occurred in 2019. 

This led to 13,300 deaths and 604,000 global disability-adjusted life years. For every 100,000 people, 1,394 were diagnosed with acute kidney stones. While there are no global projections yet, a rising chorus of experts are warning that kidney stones will rise sharply with the soaring temperatures.

“Global warming from climate change predisposes to kidney stones and acute kidney injury,” says Dr Matthew Borg, one of the authors and a biostatistician and research epidemiologist at t the University of Adelaide in Australia

Climate change can disrupt water treatment processes due to increased pollutant loads in heavy rainfall, which can decrease the availability of clean drinking water. 

“This can increase the risk of diarrhoeal diseases such as leptospirosis and schistosomiasis that, if not adequately managed, can cause dehydration and AKI,” Borg explains. 

There is already a 12% average prevalence of kidney stones worldwide, with 15% being the norm in Northern India. 

Unable to afford surgery 

Last year was the warmest year on the planet, during which India witnessed some of its deadliest heat waves. 

A report by international climate scientists found that human-induced climate change made the April 2023 heatwaves 30 times more likely in India and Bangladesh.  

Moreover, a paper published in PLOS Climate in 2023 found that heat waves can impact over 90% of India. 

Three years ago, farmworker Vandana Badame felt a cramping pain in her side and back while working in the chilli fields in Maharashtra’s Ganeshwadi village. 

“The pain was unbearable. I kept puking and thought I was going to die,” 40-year-old Badame remembers. 

The culprit was a 9mm kidney stone. The doctors suggested surgery but she simply can’t afford it.

 Since then, she has relied solely on drinking water, hoping that the stone will pass through urine. But the kidney stone has caused her tremendous pain, which increases when she works in scorching heat. 

During such times, her only solution is to immediately go to a nearby clinic, take pain management injections, and continue working in the field. 

“Even if it pains, I have to keep working. What else can I do?” asks Badame, who is her family’s sole earner. 

Every month, she relies on intravenous drips to continue working in the fields. She gets 220 Indian Rupees ($2.65) for eight hours in the field, while an intravenous drip costs her at least Rs600 ($7). 

Whenever she steps out in the field, she carries five litres of water and painkillers. As the temperature increases, so does her vulnerability to the pain caused by kidney stones. 

A 2013 paper published in the International Journal of Environmental Health Research found that “the number of hot days in a year is positively correlated with the number of urolith patients”.

 Researchers also found that drought and semi-arid conditions in India made groundwater more saline, which is associated with the formation of kidney stones. 

Moreover, a 2020 study that analyzed 1500 industrial workers from South India exposed to extreme heat had a 2.3 times higher chance of severe health outcomes, with one third of steelworkers reporting kidney stones.

Lack of health facilities 

When farmworker Basappa Kamble, 51, collapsed from kidney stone pain at 1am in 2022, it took over an hour for him to reach the hospital. 

“There are no sonography facilities in the nearby areas,” says community healthcare worker Shubhangi Kamble, who rushed him to a private hospital where a 17 mm kidney stone was detected.  

“He was hospitalized for a week,” says Kamble. Despite the surgery, he complains of recurring pain. 

In his village, Arjunwad, with less than 6000 people, a majority are farmers, farm workers, and outdoor workers exposed to tremendous heat. 

Kamble started surveying her community and found that the problem of kidney stones peaked during summers. 

Workplace guidelines

“Workplace guidelines, such as enforced work to rest ratios, reducing physically strenuous work during the hottest hours of the day, and adequate access to good ventilation and shade, should be reviewed to improve workers’ safety in hot temperatures,” suggests Borge.

Besides this, he suggests general precautions like preparing for increased presentations of kidney stones and AKI, including staffing, equipment, training, and dialysis facilities during hot seasons.

However, for its 833 million strong rural population, India just has 764 district and 1224 sub-district hospitals catering to kidney ailments. 

“Since these hospitals are overcrowded and far away from villages, the only solution for many is to take a painkiller. Its overdose has led to several side effects,” shares Kamble. 

Farmworkers are forced to rely on costly private hospitals during such pressing times and a single doctor’s visit costs at least $6. Kadam and Badame earn this money after toiling in the fields for 16 hours. 

“Many times, I avoid going to the doctor and buy medicines from the pharmacy directly,” shares Kadam. 

Frustrated with the unbearable pain, sometimes she even ties a rope around her waist, attaches it to a firm object or a hook in the wall, and pushes herself against it. 

“This comforts me for a while. Every day, I feel like there is no end to this pain, and it will only go after I die.”

Image Credits: Sanket Jain.