The study, which gathered data from 17 Middle Eastern and North African countries most vulnerable to warming temperatures—including Qatar, Bahrain, Jordan, Saudi Arabia, and the United Arab Emirates—found that climate change is making certain cancers more common and more deadly among women. Researchers looked at the prevalence and mortality of breast, ovarian, cervical, and uterine cancers, and compared the data with changing temperatures between 1998 and 2019.
They found that the prevalence of the different cancers rose from 107 to 280 cases per 100,000 people for every additional degree Celsius, with ovarian cancer cases rising the most and breast cancer the least. Mortality more than doubled, from 160 to 332 deaths per 100,000 people for each degree of temperature rise, with the greatest rise in ovarian cancer and the smallest in cervical cancer.
When the researchers broke the overall data down by country, they found that cancer prevalence and deaths rose in only six countries: Qatar, Bahrain, Jordan, Saudi Arabia, the United Arab Emirates, and Syria, speculating this may be because of particularly extreme summer temperatures in those countries. They also observed that the rise was not uniform between countries—the prevalence of breast cancer rose by 560 cases per 100,000 people for each degree Celsius in Qatar, and 330 in Bahrain. The researchers point out that while the rise in rates is small, it is statistically significant enough to suggest a notable increase in cancer risk and mortality over time.
Climate change also leaves people more exposed to environmental toxins and less likely to receive a quick diagnosis and treatment, the WHO points out, especially in developing countries disproportionately impacted by rising temperatures and infrastructural issues—leaving those populations more vulnerable to developing cancer.
“Temperature rise likely acts through multiple pathways,” said coauthor Sungsoo Chun of the American University in Cairo. “It increases exposure to known carcinogens, disrupts health care delivery, and may even influence biological processes at the cellular level. Together, these mechanisms could elevate cancer risk over time.”
As Chun pointed out, multiple factors could compound on one another to drive these rates. For example, increased heat could come in tandem with higher levels of carcinogenic air pollution.
And women are left more physiologically vulnerable to climate-related health risks, according to Chun.
“This is compounded by inequalities that limit access to health care,” she explained in the press release. “Marginalized women face a multiplied risk because they are more exposed to environmental hazards and less able to access early screening and treatment services.”
Though some could argue that better cancer screening leads to higher rates of prevalence, the researchers counter by saying improvements in screening should result in fewer deaths, as early-stage cancer is easier to treat. But since both prevalence and death rates rose, the researchers believe climate-change-related risks are the driving factors, and call for considering climate-related risks in public health planning.
“This study cannot establish direct causality,” Mataria said. “While we controlled for GDP per capita, other unmeasured factors could contribute. Nonetheless, the consistent associations observed across multiple countries and cancer types provide compelling grounds for further investigation.”
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