Petroleum is harmful at every stage of its lifecycle, from extraction to combustion to disposal. It drives climate change, poisons air and water, kills wildlife, generates persistent plastic waste, and disproportionately harms people living near refineries. Oil accounts for 33% of all greenhouse gas emissions from fuel combustion worldwide, making it the single largest contributor to the emissions heating the planet.
Climate Change and Air Pollution
Burning petroleum products (gasoline, diesel, jet fuel, heating oil) releases massive amounts of carbon dioxide into the atmosphere. That 33% share of global greenhouse gas emissions makes oil a bigger contributor than either coal or natural gas individually. These emissions trap heat, raising global temperatures and intensifying droughts, floods, hurricanes, and wildfires.
Beyond carbon dioxide, petroleum combustion produces fine particulate matter, the tiny airborne particles known as PM2.5 that penetrate deep into the lungs and bloodstream. A 2021 study published in Nature Communications estimated that 1.05 million deaths globally were avoidable in 2017 by eliminating fossil fuel combustion, which accounted for over 27% of the total health burden from particulate air pollution. These deaths come from heart disease, stroke, lung cancer, and chronic respiratory illness, concentrated in cities and industrial corridors where traffic and refinery emissions are densest.
Health Risks From Petroleum Chemicals
Petroleum contains hundreds of toxic compounds. Two of the most studied are benzene and toluene, both present in gasoline and industrial emissions. Benzene is classified as a Group 1 carcinogen, meaning it definitively causes cancer in humans through all routes of exposure. It is specifically linked to acute myeloid leukemia and other blood cancers. Even at lower levels, benzene exposure causes dizziness, headaches, skin irritation, reduced red blood cell counts, and aplastic anemia. High exposure can impair reproductive function in women.
Toluene primarily targets the nervous system. Exposure causes fatigue, sleepiness, headaches, nausea, sore throat, and eye irritation. At high concentrations it depresses the central nervous system. Pregnant women exposed to elevated toluene levels have given birth to children with attention problems and abnormalities of the head, face, and limbs.
Living Near Refineries
People who live close to petroleum refineries bear these risks most heavily. A systematic review of health studies found that every single study examining leukemia rates (six out of six) reported higher incidence and mortality among adults and children living within 7.5 kilometers of refineries, across the UK, Sweden, the US, and Taiwan. Similarly, all four cross-sectional studies examining respiratory health found consistently higher rates of asthma, chronic bronchitis, and severe shortness of breath in communities near refineries in Italy, Canada, and Jordan compared to populations farther away.
The closer you live, the worse the outcomes. Among communities within 5 kilometers of a refinery, 89% of health findings showed adverse effects, including elevated risks of cancer, stroke, coronary heart disease, respiratory emergencies, and asthma attacks. These communities are disproportionately low-income and communities of color, meaning petroleum’s health costs fall hardest on populations with the fewest resources to avoid or treat them.
Oil Spills and Marine Wildlife
Crude oil is acutely toxic to marine life. When spills occur, the damage ripples through ecosystems for years. The Exxon Valdez spill in Alaska killed several thousand sea otters and significantly impacted local killer whale populations. The Deepwater Horizon spill in the Gulf of Mexico killed at least 160 marine mammals directly, but the longer-term reproductive effects were even more devastating.
Bottlenose dolphins in the heavily oiled Barataria Bay, Louisiana, saw their reproductive success collapse after the Deepwater Horizon disaster. Over a 47-month monitoring period, only 20% of pregnant dolphins in the contaminated area produced viable calves, compared to 83% in a reference population. Dolphins in Mississippi Sound, another oil-contaminated area, had a nearly identical reproductive success rate of just 19.4%. Annual survival rates for dolphins in the most affected areas dropped to 80-85%, well below the 95% average at uncontaminated sites.
Oil exposure in marine mammals causes a cascade of problems: immune suppression, blood disorders, lung disease, neurological damage, eye irritation, adrenal dysfunction, and behavioral changes. Studies on mink, used as stand-ins for protected sea otters, showed that dietary exposure to crude oil beginning before breeding led to fewer births, fewer live offspring, and poor survival to weaning. Following major spills, harp seals produced fewer pups and harbor seals experienced abnormally high rates of miscarriage and premature births.
The Plastic Problem
Petroleum is the primary raw material for plastic, and the sheer scale of plastic pollution now qualifies as a planetary crisis. Roughly 99% of plastics are derived from fossil fuels, mostly oil and natural gas. Once produced, plastic persists in the environment for centuries, breaking down into smaller and smaller fragments called microplastics rather than decomposing.
The numbers in the ocean are staggering. Research published in Environmental Science and Pollution Research estimated that between 1.5 and 4.7 billion tonnes of microplastic particles are currently present in the marine environment, with total particle counts in the trillions. These microplastics have been found in every ocean habitat, from surface waters to deep-sea sediments. Marine animals ingest them, and the particles work their way up the food chain. Microplastics have now been detected in human blood, lung tissue, and placentas, though the long-term health consequences are still being studied.
The Hidden Cost of Subsidies
One reason petroleum remains so dominant despite these harms is that governments worldwide subsidize it heavily. The International Monetary Fund estimated that global fossil fuel subsidies reached $5.9 trillion in 2020, equivalent to 6.8% of global GDP. Only 8% of those subsidies were direct payments or tax breaks. The remaining 92% were “implicit” subsidies, meaning the price of petroleum products doesn’t reflect the true costs they impose on society through air pollution, climate damage, traffic congestion, and healthcare spending.
In practical terms, this means you pay for petroleum’s damage twice: once at the pump and again through taxes, health insurance premiums, disaster recovery costs, and environmental cleanup. If petroleum were priced to reflect the harm it causes, alternatives like electric vehicles, heat pumps, and renewable energy would be far more competitive than they already are.