Gasoline is harmful in nearly every phase of its lifecycle: breathing its vapors damages your lungs and brain, its chemical components cause cancer, burning it releases roughly 8.9 kilograms (about 20 pounds) of carbon dioxide per gallon, and spilling it contaminates soil and drinking water for years. The risks aren’t limited to dramatic accidents or industrial disasters. Everyday exposure, from filling your tank to breathing roadside air, carries real consequences.
What’s Actually in Gasoline
Gasoline isn’t a single substance. It’s a blend of hundreds of hydrocarbons, and several of them are independently toxic. The most dangerous is benzene, a known carcinogen that increases the risk of leukemia and other blood disorders. Benzene exposure comes not just from pumping gas but from cigarette smoke, which accounts for about half of all benzene exposure in the U.S. population. Among smokers, 90 percent of their benzene exposure comes from the cigarettes themselves.
For decades, gasoline also contained an additive called MTBE, introduced in the late 1980s to help fuel burn more cleanly. MTBE turned out to be a groundwater nightmare: it dissolves easily in water, doesn’t cling to soil, and migrates faster and farther underground than other gasoline components. It’s also very persistent and expensive to clean up once it reaches a water supply. The U.S. phased out MTBE after the Energy Policy Act of 2005 replaced the oxygen requirement with a renewable fuel standard, shifting to ethanol instead.
How Gasoline Vapors Harm Your Body
When you inhale gasoline fumes, the volatile compounds dissolve in the moist lining of your airways and trigger an inflammatory response. Short-term exposure at a gas station or in a poorly ventilated garage can cause headaches, nausea, dizziness, and a feeling of disorientation. These symptoms are consistent with what toxicologists call transient central nervous system depression: the chemicals temporarily suppress normal brain function.
Chronic exposure is far more serious. A study of 50 gas station workers compared to 49 unexposed controls found significant drops in red blood cell counts, hemoglobin levels, and packed cell volume among the exposed group. Their white blood cell counts were significantly elevated, a sign the immune system was reacting to ongoing chemical stress. These changes appeared in workers with as little as one to ten years of exposure and persisted in those who had worked over a decade.
Cancer Risk From Benzene
Benzene’s link to leukemia is one of the most well-established chemical-cancer connections in toxicology. The National Cancer Institute identifies benzene as a substance that increases the risk of leukemia and other blood disorders. Workers in industries that produce or use benzene face the highest exposure levels, though federal regulations have reduced those exposures over time. Limits on benzene content in gasoline have also helped lower population-wide risk, but the compound hasn’t been eliminated from fuel entirely.
Brain and Nerve Damage
The neurological effects of gasoline go well beyond a temporary headache. Research published in the journal Brain compared chronic gasoline sniffers, former sniffers, and people with no exposure history. Current sniffers showed impaired coordination (difficulty walking heel-to-toe, trouble with rapid hand movements, and problems touching their nose accurately), postural tremor, and exaggerated reflexes. Cognitively, they performed worse on tests of visual attention, visual memory, and the ability to associate visual patterns with locations.
Former sniffers who had stopped still showed some of these deficits, particularly impaired balance and visual memory, though their symptoms were less severe. The severity of both neurological and cognitive problems correlated directly with how long someone had been exposed and with the lead levels in their blood. This suggests the damage is dose-dependent: more exposure means worse outcomes, but stopping does allow partial recovery.
Skin and Nail Damage From Direct Contact
Liquid gasoline strips the natural oils from your skin. A study comparing workers with regular gasoline contact to unexposed controls found dramatically higher rates of skin and nail problems. Workers were three times more likely to develop thickened, roughened skin (hyperkeratosis), three times more likely to have chronic dryness, five times more likely to develop dermatitis, and over eleven times more likely to have nail disorders. Cracked skin and brittle, ridged nails were the most common symptoms. The mechanism is straightforward: gasoline dissolves the lipid barrier in the outermost layer of skin, leaving it vulnerable to cracking and infection.
Air Pollution and Particulate Matter
Burning gasoline doesn’t just produce carbon dioxide. Combustion of gasoline, diesel, and other fuels is a major source of fine particulate matter, the tiny particles known as PM2.5 that penetrate deep into lung tissue. The California Air Resources Board identifies gasoline combustion as one of the primary sources of PM2.5 in outdoor air. These particles are small enough to pass through the lungs and into the bloodstream, contributing to heart disease, stroke, lung cancer, and respiratory conditions like asthma.
Gasoline engines also emit nitrogen oxides and volatile organic compounds that react in sunlight to form ground-level ozone, the main ingredient in smog. PM2.5 further degrades air quality by scattering and absorbing light, reducing visibility. In dense urban areas, the cumulative effect of millions of vehicles burning gasoline creates a persistent blanket of pollution that disproportionately affects people living near highways and high-traffic corridors.
Carbon Emissions and Climate Impact
Every gallon of gasoline burned produces 8,887 grams of CO2, just under 20 pounds. That number, agreed upon by the EPA and the Department of Transportation, accounts for all the carbon in the fuel being converted to carbon dioxide during combustion. For context, the average American car driving 12,000 miles a year at 25 miles per gallon releases roughly 4.3 metric tons of CO2 annually from fuel alone. This doesn’t include the emissions from extracting, refining, and transporting the gasoline before it ever reaches your tank.
Transportation accounts for the largest share of greenhouse gas emissions in the United States, and gasoline-powered passenger vehicles are the single biggest contributor within that sector. The CO2 released traps heat in the atmosphere, driving the warming that intensifies heat waves, shifts rainfall patterns, raises sea levels, and disrupts ecosystems worldwide.
Groundwater and Soil Contamination
Gasoline doesn’t have to be burned to cause environmental damage. Leaking underground storage tanks at gas stations have been contaminating soil and groundwater for decades. Once gasoline enters the ground, its components spread through the water table. MTBE was especially problematic because it traveled faster and farther than other gasoline chemicals and proved extremely difficult to remove from contaminated aquifers. Even with MTBE largely phased out, other gasoline compounds like benzene, toluene, and xylene still pose contamination risks when tanks leak or fuel spills occur.
Research has also highlighted that leaking storage tanks are not evenly distributed. Communities with lower incomes and higher proportions of minority residents tend to bear a disproportionate share of contamination, creating an environmental justice issue layered on top of the public health risk. Cleanup is slow, expensive, and sometimes incomplete, meaning affected communities can face contaminated drinking water for years.