Municipal solid waste, the everyday trash generated by households and businesses, causes a wide range of harms to human health, water supplies, soil, air quality, and ecosystems. The world currently produces about 2.01 billion tons of it each year, and the World Bank projects that figure will climb to 3.40 billion tons by 2050. Much of this waste is poorly managed, and the consequences ripple outward from dump sites and landfills into surrounding communities and, eventually, into oceans.
Respiratory Problems Near Landfills
People living near active landfills consistently report higher rates of breathing difficulties. When residents near waste sites smell hydrogen sulfide (the “rotten eggs” odor) or the smell of decomposing garbage, they are more likely to wheeze and experience shortness of breath. Studies reviewed by the Agency for Toxic Substances and Disease Registry documented a moderate decline in lung function on days when nearby residents noticed these odors. The connection is strong enough that communities near landfills frequently report elevated rates of asthma and other chronic respiratory conditions.
Beyond the gases, particulate matter from waste handling, truck traffic, and open burning of trash adds to local air pollution. In lower-income countries where open dumping is common, burning waste releases fine particles, carbon monoxide, and toxic compounds that can travel well beyond the dump site itself.
Water Contamination From Leachate
When rain filters through buried waste, it picks up dissolved chemicals and forms a toxic liquid called leachate. This fluid contains heavy metals including arsenic, mercury, cadmium, lead, copper, nickel, and chromium. Measurements from landfill leachate have found concentrations of iron at 1.19 mg/L, chromium at 0.33 mg/L, and detectable levels of lead, cadmium, and zinc. If leachate reaches groundwater or nearby streams without treatment, these metals accumulate in drinking water sources.
Leachate also carries microplastics. Polypropylene, polystyrene, nylon, and polycarbonate are among the most common plastic fragments found in landfill runoff. Newer landfills tend to release higher concentrations of microplastics than older ones, likely because modern waste streams contain far more plastic packaging. Once these particles enter waterways, they are extremely difficult to filter out and can persist in the environment for centuries.
Mosquito-Borne Disease
Improperly managed waste creates breeding grounds for disease-carrying insects. Plastic containers, rubber tires, and other discarded items collect pooled rainwater, which is exactly the habitat mosquitoes need to reproduce. A Stanford University study found that hot spots for mosquito-borne illness were closely associated with litter accumulation near homes.
The diseases linked to waste-related mosquito breeding include dengue, chikungunya, and malaria. This is especially dangerous in tropical and subtropical regions where the Aedes aegypti mosquito, which spreads dengue and chikungunya, has adapted to breeding in human-made water containers in urban areas. Rats, flies, and other pests also thrive around waste dumps, spreading gastrointestinal infections and other illnesses to nearby populations.
Soil Degradation
Long-term dumping changes the chemistry of surrounding soil. Studies of dump sites in Poland found that soil pH at waste sites ranged from 5.0 to 7.4, with active landfill areas trending more alkaline (around 7.4) compared to nearby forested land, which measured around 5.0 to 5.4. This shift in acidity affects which plants can grow and how well soil organisms function. Heavy metals from leachate also bind to soil particles over time, making land unsuitable for agriculture long after a dump site closes. Crops grown in contaminated soil can absorb these metals and pass them into the food chain.
Ocean Plastic Pollution
Roughly one-quarter of all plastic waste globally is “mismanaged,” meaning it is not recycled, incinerated, or stored in sealed landfills. This mismanaged waste is vulnerable to washing into rivers and eventually the ocean. Between 1 and 2 million tons of plastic enter the oceans every year. How much of a region’s waste reaches the sea depends on proximity to coastlines and rivers, local rainfall, and terrain.
Once in the ocean, plastic waste harms marine life through ingestion and entanglement. Seabirds, turtles, fish, and marine mammals mistake plastic fragments for food. Over time, larger pieces break into microplastics that work their way through the food web, from plankton up to the fish species humans eat. The scale of the problem is enormous: the world produces around 350 million tons of plastic waste annually, and even though only about 0.5% of it reaches the ocean, the cumulative effect over decades has created massive floating debris fields and contaminated seafloor sediments worldwide.
Property Values and Economic Harm
Living near a landfill carries a measurable financial cost. A study of a Minnesota landfill found that property values dropped about 12% at the landfill boundary and roughly 6% one mile away. Research on a landfill in Pepperell, Massachusetts, showed that a typical home half a mile from the site would gain about 6% in value simply by being located a mile away instead. Even at a mile and a half, moving an additional half mile added another 1% to home value.
These losses hit hardest in lower-income communities, which are disproportionately located near waste facilities. Beyond property values, poorly managed waste sites can reduce tourism, discourage business investment, and burden local governments with cleanup costs that stretch over decades.
Risks for Waste Workers
The people most directly harmed by municipal solid waste are those who handle it. Formal waste collection workers face higher rates of respiratory illness, musculoskeletal injuries, and skin infections compared to the general population. But the risks are far greater for the estimated 15 to 20 million informal waste pickers worldwide who sort through open dumps without protective equipment. These workers are regularly exposed to sharp objects, biological waste, chemical residues, and heavy vehicle traffic. Skin infections, chronic coughs, and gastrointestinal illness are common occupational hazards in this population, compounded by lack of access to healthcare.
Greenhouse Gas Emissions
Decomposing organic waste in landfills produces methane, a greenhouse gas roughly 80 times more potent than carbon dioxide over a 20-year period. Landfills are one of the largest human-related sources of methane emissions globally. When food scraps, yard waste, and paper break down in the oxygen-free conditions inside a landfill, they generate methane continuously for years. Modern engineered landfills capture some of this gas, but older and unmanaged dump sites release it directly into the atmosphere, contributing meaningfully to climate change.
Open burning of waste, still common in many parts of the world, adds carbon dioxide, black carbon, and a range of toxic pollutants to the air. These emissions worsen local air quality while also accelerating global warming.