Climate change, water scarcity, and sewage pollution converge in northern Iran.

In recent years, global warming and accelerating climate change have drastically reduced groundwater and surface water across Iran. Prolonged droughts, driven by declining rainfall, have caused rivers to dry up and reshaped entire agricultural landscapes.

In a developing country like Iran, population growth policies have sharply increased water consumption, while sewage production has risen alongside it. As freshwater sources disappear, domestic and industrial wastewater now flows into dried riverbeds and has become a primary water source for agriculture and livestock. This shift has pushed farming into a dangerous new phase—one where sewage and chemical contamination expose communities to rising rates of gastrointestinal and other cancers.

Visual Researcher Kianoush Saadati was born and raised in an agricultural community in northern Iran and grew up closely connected to the land. Several years ago, a small dam was built in their village to collect surface water for fish farming and crop irrigation. Today, that same dam—spanning 70 hectares—is filled with domestic and industrial sewage. It supplies water to more than 300 hectares of farmland, where farmers produce over 1,000 tonnes of rice and raise more than 200 tonnes of fish each year.

Effluents containing heavy metals pose severe risks to ecosystems and all living beings. Wastewater enters human and animal food chains, silently damaging immune systems and vital organs such as the lungs, kidneys, and stomach. According to the International Agency for Research on Cancer (IARC), northern Iranian provinces recorded the country’s highest rates of lung and gastrointestinal cancers in 2018, with water pollution and poor hygiene identified as leading causes.

Built in 1984, the Mohammadabad village reservoir lies four kilometres from the city of Gorgan. Originally covering 30 hectares, it has expanded to 70 hectares and continues to grow, now filled largely by municipal and industrial sewage.

Each winter, local fishermen harvest more than 200 tonnes of fish during a single month-long season. Most are informal workers without health insurance, who fish in winter and cultivate rice paddies in spring and summer. While fish is widely valued for its omega-3 fatty acids and its role in cancer-preventive diets, fish raised in contaminated water accumulate mercury and other heavy metals in their fat and flesh—making them a significant source of carcinogenic exposure.

Every year, this man will buy fish from the dam to distribute to other cities and provinces.
The fish market will sell the produce of this sewage-filled dam for at least two months.
Mohammed, 30, a driver from the village of Yampi, pauses to perform his noon prayer on the wall of the reservoir before transporting fish to other cities.
Qayyum, 15, and Mehrdad, 10, guard the rice fields from birds, working from 6 a.m. to 6 p.m. They rest on makeshift beds of rice straw and earn $50 over two months to help support their parents.
Ali, 32, from Mohammadabad village, washes himself in wastewater after spreading paddy seeds in the fields. Exposure to sewage is a major cause of infectious diseases and cancer.

After the rivers dry up, municipal and industrial sewage flows into the riverbeds, carrying heavy metals and pollutants such as dioxin, a major cause of cancer. Workers use gypsum and lime to adjust the water’s pH, kill oxygen-consuming bacteria, and prevent mass fish deaths caused by low oxygen and algal growth.

Hamid, 50, oversees fish farming at the reservoir. On hot days, he spreads up to five tonnes of construction plaster and lime into the water to counter oxygen depletion caused by sewage, detergents, and algal growth.

The extensive paddy fields mean workers start their day at 5 a.m., wearing protective clothing to reduce exposure to infectious diseases as they farm using sewage-irrigated land.

In Mohammadabad and surrounding villages, each year sheep suffer abortions each year due to contaminated water, also lead to mass fish deaths.

Hussein, 55, from Mohammadabad village, served as the guardian and water distributor of the village reservoir. He died in 2019 from intestinal infection and cancer.
Azim, 23, from the village of Ghorbanabad, 10 kilometres from Gorgan, has been diagnosed with colon cancer and has undergone chemotherapy at 5th Azar Hospital.
Water contamination caused an infection that cost a rice worker their toe.
Taleghani Hospital has painted murals on the walls of the children’s ward to provide relief and reduce stress during treatment.
Mohammed Matin, 6, from Gorgan, has a genetic disorder doctors link to his mother’s exposure during pregnancy to pesticide- and heavy-metal-contaminated water.
Nuclear imaging is one way to identify bone metastases.
Nurses hold a birthday party for a child undergoing cancer treatment at Taleghani Hospital in Gorgan to lift morale.
A nurse at 5 Azar Hospital in Gorgan prepares chemotherapy drugs under a safety hood before administering them to patients.
Rice grown with wastewater is used in Muharram ceremonies, often without people knowing how the crop was produced.
After hunting migratory birds, hunters skin them and discard the unusable parts.
Fishermen are aware of water pollution and always carry water with them for washing.
Ahmed, 33, works as a dam guard, moving through the reservoir by boat at night to circulate the water, increase oxygen levels, and reduce fish deaths.
Aziz, 34, takes off his fishing clothes for lunch.
Sewage has darkened the water and contaminated all the fish with heavy metals, while sediment continues to build up year after year.
Saleh, 33, is from the village of Mohammadabad. After finishing fishing, he is no longer interested in working in the dam.
Mustafa, 75, believes the sewage water is safe and works in his fields without boots or protective clothing, setting an example to ease the stress and fears of other workers.
Komeil, 35, washes his clothes in the reservoir after fishing, even though the sewage often damages clothing and allows contaminated water to infiltrate.