The fishing communities of Sri Lanka are facing an alarming health crisis. According to a recent report published in The New York Times, young men in their 30s and 40s have been turning up at hospitals with late-stage kidney failure, needing dialysis or even transplants. In some communities, as many as one in five young men is affected. Although the exact cause of their condition is not clear, experts say the illness is most likely the result of exposure to extreme heat, exacerbated in recent years by climate change, among other reasons.
Similarly, a new study published in the journal Nature Communications shows that climate change is directly affecting the survival of newborns in low- and middle-income countries, with 4.3% of neonatal deaths during the study period (2001-2019) attributed to non-optimal temperatures with both high and low ambient temperatures posing a risk.
The list goes on. The International Labour Organization (ILO), in its report ‘Ensuring Safety and Health at Work in a Changing Climate’, highlights that the global workforce is facing a serious health crisis due to the negative impacts of climate change. The report says that the climate crisis could expose 2.4 billion workers to health hazards like cancer, cardiovascular illness, kidney dysfunction, and physical injury. It says that excessive heat affects 70% of the global workforce of 3.4 billion people. Amid such an evident and real threat of climate change, it becomes imperative to understand how the ramifications of the phenomenon, directly and indirectly, impact human health worldwide.
Crisis is real
Experts say climate change is intimately linked to our health, habits and well-being. It is affecting and influencing the food we eat, the water we drink, the air we breathe, and the weather we experience —all of which pose a health risk. “The impact can be as direct as physical injury caused by floods and hurricanes or it can be as insidious as the long-term harm caused by global warming and worsening air pollution,” says Dr Vineet Talwar, director of medical oncology at Rajiv Gandhi Cancer Institute and Research Centre, Delhi.
It has been seen that changes in humidity, temperature and particulate pollutants in the air affect the respiratory and cardiovascular systems, especially in those with underlying heart or lung ailments. Rising temperatures lead to heat-related illnesses including heat stroke, cardiovascular problems and kidney disease. Extreme weather events like floods and hurricanes can cause injuries, drownings, and mental health issues.
Air pollution, exacerbated by climate change, increases respiratory diseases and allergies. Vector-borne diseases such as malaria and dengue fever spread to new areas as temperatures rise. Food and water insecurity resulting from changing weather patterns can lead to malnutrition and waterborne illnesses.
“The health impacts of climate change are wide-ranging and affect vulnerable populations disproportionately, including children, the elderly, and those in low-income areas,” says Dr Rakesh Gupta, senior consultant, internal medicine, Indraprastha Apollo Hospitals, Delhi.
Dr Sameer Punia, senior consultant, paediatric intensivist, Aakash Healthcare in Delhi, also notes that the effects of climate change on mother and infant health are both direct and indirect. “Unfavourable health consequences, including miscarriage, low birth weight, starvation, and respiratory illness, can result from exposure to stressors associated with the environment,” he says.
Kidney diseases
A recent report in The Lancet has found that chronic kidney disease patients living in the hottest countries experienced an additional 8% drop in kidney function each year compared to those living in temperate climates. Additionally, for every 1 degree Celsius rise in temperature, the estimated risk of hospitalisation for renal diseases lasting up to 7 days increased by 0.9%, affecting mostly children, women, and the elderly population, according to a study of ambient temperature and hospitalisation for renal diseases in Brazil during 2000–2015. According to scientific data, a 1 degree-Celsius increase in temperature increases the risk of kidney failure by 1.1% and the risk of death from kidney failure, urolithiasis, acute kidney injury (AKI), and urinary tract infection (UTI) by 3.1%.
So how is the kidney becoming a direct victim of climate change? “As the temperature rises, there are increased chances of dehydration, and gastrointestinal infections. It can cause people, especially those working in extreme climates, to have heat stroke and impact their kidneys,” says Dr Vikram Kalra, consultant nephrologist, CK Birla Hospital, Delhi.
“Heat stress, a direct consequence of rising temperatures, can lead to chronic kidney disease by causing repeated dehydration and electrolyte imbalances. The kidneys are especially vulnerable due to their role in fluid regulation and waste removal,” explains Dr Gupta of Indraprastha Apollo Hospitals. “When the kidneys lack adequate water, they enter a shock state, producing less urine, which results in acute kidney injury. Significant damage to the kidneys from acute kidney injury can lead to chronic kidney disease in the future,” further elaborates Dr Sanjiv Saxena, chairman of PSRI Institute of Nephrology in Delhi.
Neonatal deaths
The study published in Nature Communications categorically says that climate change was responsible for 32% of heat-related neonatal deaths while simultaneously decreasing the toll from cold temperatures by 30%.
Paediatricians explain how climate change can cause neonatal deaths. Dr Poonam Sidana, director of neonatology and paediatrics at CK Birla Hospital in Delhi, says newborn babies are vulnerable as their body cannot control their temperature.
“Even in a healthy newborn, we say that if you keep the baby in a cold environment, the baby will get cold very easily. They have a high surface area, they are not able to curl up like what we adults can do and they are not able to shiver and generate heat,” she explains, adding that they cannot sweat either. Hence, higher temperatures put a demand on their vulnerable and
under-developed physiology and thermoregulatory systems, and they get dehydrated very quickly which can cause electrolyte imbalances, hyperthermia, lethargy, feeding less, and higher heat rates, causing more oxygen demands, also leading to thromboembolism (blood clot). “This can result in severe complications such as seizures, organ failure and death,” explains Dr Gupta of Indraprastha Apollo Hospitals.
Maternal heat stress during pregnancy can lead to preterm birth and low birth weight, increasing neonatal mortality risks. Climate-driven food insecurity may also contribute to maternal and neonatal malnutrition, further compromising newborn health and survival, doctors say. At the same time, they note that air pollution exacerbated by climate change can cause respiratory distress in newborns and cause development problems.
It is needless to highlight that extreme weather events may disrupt healthcare services, affecting neonatal care. Extreme weather events and food insecurity due to climate change can lead to malnutrition and hindered growth, further increasing the risk of neonatal deaths, says Dr Punia of Aakash Healthcare in Delhi.
Cancer development
Research shows that climate change cannot just increase the occurrence of cancer but also have a detrimental impact on its diagnosis, treatment, and overall care. Dr Mandeep Singh Malhotra, director of surgical oncology at CK Birla Hospital in Delhi, says with temperature rise, particulate matter in the air will also increase and persist for a longer period, and cases of cancer-related to air pollution, oral cancer, lung cancer, food pipe cancer, and cervical cancer will increase.
He also says that virus-induced cancers by HPV, EBV (Epstein-Barr virus), and Hepatitis virus will increase with their virulence. With an enlarged hole in the ozone layer, and increased penetration of UV rays, instances of skin cancer will be higher. “It increases the risk of skin cancer and the kind of aggressive skin cancer known as melanoma by about 25% when the ozone layer is damaged,” says Dr Puneet Gupta, chairman, oncology, Asian Hospital, Faridabad.
The carcinogenic effect of pesticides and contaminants in water will be higher as high temperature increases their chemical reaction and oxidation, he says, adding, “smog or industrial waste, pesticides, and herbicides, everything becomes more potentiated when there is a higher temperature. That is what is hypothesised that this would cause an overall increase in cancer.”
He also says that toxins released by fungi in the air such as aflatoxins which cause lung cancer or aspergillosis, will increase resulting in higher cases of lung-related cancer and other diseases. Immunity in particular gets reduced with heat and heat strokes, especially in vulnerable populations like children and the elderly increasing the mortality of cancer. In terms of diagnosis and treatment, doctors say that screening will have to be heightened and tolerance to treatment, chemotherapy, radiation, and recovery from surgery will be reduced resulting in the recurrence of cancer. “Climate change is closely interwoven with not only the etiology of cancer but also treatment tolerance and compliance among cancer patients,” comments Dr Talwar of Rajiv Gandhi Cancer Institute and Research Centre.
“By 2030, there is going to be a global cancer epidemic. If global warming rises to 1.5 degrees, then this deadly combination will be catastrophic to many human populations all around the globe,” warns Dr Gupta of Asian Hospital.