In the core of large cities—from New York to Nairobi, Mumbai to Mexico City—healthcare providers are dealing with more than just fevers, injuries, or ongoing illnesses. Increasingly, they are confronting ailments linked to environmental exposure. From asthma associated with air pollution to cancers connected to industrial toxins, doctors are observing the effects of environmental deterioration on human health firsthand. For many, this reality shifts their role from caregivers to advocates—environmental defenders in white coats.

Physicians frequently address the fallout from environmental negligence. In children’s wards, they treat young patients afflicted with asthma caused by pollution. In cancer treatment centers, they notice clusters of cancer near industrial areas. In emergency rooms, they respond to heat-related illnesses and cardiovascular incidents during urban heatwaves. These are not isolated incidents—they are precursors from a planet under strain.

Doctors are especially positioned to take action. With significant public trust and access to clinical data, they act as credible voices of concern. When healthcare facilities report increases in respiratory conditions during smog periods or pediatricians raise alarms about lead contamination in water, it becomes challenging for policymakers to overlook. Trained to spot patterns, determine root causes, and advocate for patients, physicians naturally become environment advocates.

This change is already underway. In Flint, Michigan, pediatricians were instrumental in revealing the lead water crisis. In Delhi, doctors campaigned for reforms related to air pollution. In Nairobi, health professionals are pushing for improved waste management in informal neighborhoods. These initiatives have resulted in tangible outcomes—from prohibitions on hazardous materials to enhanced public health regulations.

Significantly, activism does not entail forsaking clinical duties. It can start with informing patients about environmental hazards, collaborating with local health authorities, and utilizing platforms—from medical journals to social media—to strengthen evidence-based advocacy.

Environmental health is synonymous with public health. And in urban areas where millions contend with unseen toxic hazards, it may be healthcare providers—not solely activists or officials—who spearhead the movement for cleaner, safer, healthier city living. By tackling the fundamental causes of disease, medical professionals can assist in healing not just individuals—but entire communities.

Stephen Gitonga is an author and an expert in energy and environmental matters.