This super-detailed map shows the most toxic air in the county, down to the block

In Baytown, Texas, just east of Houston, the air is filled with pollution from dozens of industrial plants in the area, including heavy metals from an ExxonMobil refinery and ethylene oxide from chemical plants. All of the pollution amplifies the additional cancer risk of living in the city, and the risk can vary block to block.

It’s one hot spot, among more than a thousand that ProPublica mapped out in a new report that looks at cancer-causing air pollution from industrial sources across the country. Some of the worst are in Texas, and most are in the South, where environmental regulations are weak. The risk is higher in census tracts where the majority of residents are black.

Even though the Clean Air Act sets standards for a small group of pollutants, such as ground-level ozone and lead, 187 other hazardous pollutants don’t have the same limits. Also, the Environmental Protection Agency (EPA) doesn’t look at the cumulative effect of multiple pollutants from different sources in a particular area.

The map shows those details, as the ProPublica story explains:

At the map’s intimate scale, it’s possible to see up close how a massive chemical plant near a high school in Port Neches, Texas, laces the air with benzene, an aromatic gas that can cause leukemia. Or how a manufacturing facility in New Castle, Delaware, for years blanketed a day care playground with ethylene oxide, a highly toxic chemical that can lead to lymphoma and breast cancer. Our analysis found that ethylene oxide is the biggest contributor to excess industrial cancer risk from air pollutants nationwide. Corporations across the United States, but especially in Texas and Louisiana, manufacture the colorless, odorless gas, which lingers in the air for months and is highly mutagenic, meaning it can alter DNA.

Explore the full map here.