10 Dirtiest Cities in the U.S. (L.A. Shockingly Isn't One of Them)

As of June 24, 2024, San Bernardino claims the top spot on the list of the United States' dirtiest cities. With the worst median air quality in the country — often exceeding limits set by the Environmental Protection Agency (EPA) — the city's polluted air and greenhouse gas emissions make life tough for residents.

Additionally, drinking water contaminants and a high number of overcrowded homes contribute to poor living conditions in San Bernardino.

The city's prominent role in the shipping industry only exacerbates these issues. Located in California's Inland Empire, the city faces heavy pollution from its freight corridor which sees thousands of diesel-fueled commercial trucks passing through on a daily basis.

Detroit faces a multitude of problems that extend beyond air pollution. According to LawnStarter's data, the city has the highest percentage of homes without complete plumbing facilities (12.7 percent) and without complete kitchen facilities (15.6 percent), increasing the risks of disease control issues.

With a high share of residents reporting dissatisfaction, Detroit is dirty in many ways, from its trash heap of environmental challenges to its auto commuter struggles (long commutes, low-quality roads and high fuel consumption). The city's poor waste management and unhealthy air quality further compound all of these issues.

Reading ranks third, largely due to its sky-high greenhouse gas emissions per capita (18.5 metric tons) and being one of the top cities with residents dissatisfied with their city's overall cleanliness. Although the city may not have severe issues with near-roadway pollution, residents overwhelmingly find the city dirty and rank it poorly for resident satisfaction.

Reading also suffers from high polluted air levels and challenges with waste management, such as high levels of landfill waste and inadequate recycling infrastructure.

According to LawnStarter, Reading ranks No. 60 in terms of recycling collectors per 100,000 residents, which makes it difficult for the city to handle its waste effectively.

Newark lands at number four, primarily due to its high levels of air pollution and ranking No. 1 in annual excess fuel consumption per auto commuter, with 23 gallons (87 liters) wasted per driver each year.

Despite being located near cleaner cities like Jersey City, Newark struggles with meeting air quality standards and ranks No. 4 in terms of resident dissatisfaction, with 88.9 percent of residents reporting that they find the city dirty.

Ultimately, it's Newark's dense population and industrial activity that contribute most to its high noxious air levels, making it challenging for residents to contend with these poor environmental conditions on a daily basis.

Like San Bernardino, Ontario suffers from the freight corridor in California’s Inland Empire. The city ties for the worst median air quality, with an Air Quality Index (AQI) value of 80 and 21.6 percent of residents exposed to near-roadway pollution.

But Ontario's issues extend beyond air pollution: It ranks poorly in resident satisfaction, with 60.7 percent of residents dissatisfied with the city’s handling of pollution. Frequent drinking water violations and inadequate waste management practices contribute to these concerns.

While Ontario is pushing for green policies, such as reducing emissions, there is still a long way to go to improve the overall living conditions there.

Despite its thriving job market, Phoenix ranks No. 6 due to poor air quality and significant landfill waste. The city struggles with pollution, ranking No. 20 overall, and wildfire smoke from nearby regions exacerbates its noxious air.

The Environmental Protection Agency has set guidelines to address air quality, but Phoenix continues to fall short of meeting those standards.

Additionally, 47.8 percent of residents express dissatisfaction with the city's handling of waste management and the resulting health consequences ranging from asthma to respiratory diseases, which pose challenges for local disease control efforts.

About 40 miles southwest of Newark and 60 miles from Jersey City, Trenton struggles with pollution and infrastructure issues, ranking No. 7 among America’s dirtiest cities. The city has one of the highest rates of residents dissatisfied with pollution, with 47.7 percent expressing dissatisfaction.

Trenton also faces challenges with waste management, contributing to its poor environmental conditions. And greenhouse gas emissions per capita are notably high (8.4 metric tons), placing Trenton No. 14 in pollution ranking and making air quality a persistent issue for the city.

While Las Vegas might distract some with its bright lights, the city struggles with dirty air and poor waste management.

Las Vegas faces heavy air pollution, ranking No. 31 in pollution, largely due to vehicle emissions and nearby oil refineries. The influx of tourists also adds to the burden on local waste facilities, and the city ranks No. 110 for living conditions.

Despite the city having implemented some green policies (such as investments in renewable energy and a water-conserving landscaping program), 46.8 percent of residents express dissatisfaction with how the city handles its water quality and pollution, contributing to its poor ranking in resident dissatisfaction levels (No. 53 overall).

Houston’s bustling industrial sector, including oil refineries, places it among the nation’s dirtiest cities, ranking No. 12 for pollution. The city struggles with air pollution and a poor track record for drinking water violations, contributing to resident dissatisfaction, which ranks No. 50 overall.

Though Houston has made strides in green policies (like expanding its electric vehicle infrastructure and promoting energy-efficient building codes), 46.7 percent of residents report dissatisfaction with local pollution control, and increasing health risks from polluted air land the city in No. 9 place overall in the LawnStarter study.

Baytown, Texas, is a small city with big pollution problems. With the highest greenhouse gas emissions per capita (it ranks No. 1), Baytown is home to several large refineries that contribute to unhealthy air quality.

The city also ranks 122nd for waste management, making it a trash heap waiting for improvement. Despite efforts to restrict emissions, Baytown still ranks poorly in air quality and resident dissatisfaction, placing it No. 107 in the latter category.

Local green policies include efforts to increase the use of renewable energy sources, such as implementing wind and solar power, along with initiatives to reduce industrial emissions through stricter regulations on the refineries.

These policies aim to curb greenhouse emissions and improve the quality of the air over time, though the city's heavy industrial activity has limited their impact.

By now you might be wondering which American cities LawnStarter ranked as the cleanest. In fact, several stood out for their cleanliness and strong environmental policies.

Cities like Wilmington, North Carolina, and Pleasanton, California, rank among the least dirty cities, due to their low levels of air pollutants, efficient management of waste and efforts to restrict emissions.

These cities enjoy higher resident satisfaction and face fewer health consequences (such as asthma and other respiratory issues), thanks to lower levels of pollution near roadways and compliance with EPA safety guidelines.

Duluth, Minnesota, and Lynchburg, Virginia, also exemplify how cleaner air, lower greenhouse gas emissions and minimal drinking water violations can create healthier living environments. These cities benefit from strong local policies that maintain their air quality standards and support sustainable living, allowing them to avoid the environmental pitfalls you come across in larger, more polluted cities.

As a result, residents of these cities enjoy cleaner day-to-day conditions and report higher satisfaction with their local services and infrastructure, according to LawnStarter.

We created this article in conjunction with AI technology, then made sure it was edited and fact-checked by a HowStuffWorks editor.