Last month, Forbes rated and ranked the most toxic cities in the United States–the portrait painted was distressingly grim with the worst offender spewing 11.3 million pounds of on-site toxic releases into the atmosphere in 2009. (Read more about it here: America’s 10 Most Toxic Cities.) Many readers were eager to know more about the other end of the spectrum–the cities that fared the best for being the least toxic–and Forbes complied with a new list.
For the new rankings, they began with the 80 largest Metropolitan Statistical Areas (MSA) which have data on toxicity levels, they then rated these areas based on five measures of pollution and toxicity.
Two of the measures were calculated using data from the EPA:
The Air Quality Index (AQI) measures the number of days air quality in each of these metros rose above 100 on an EPA index. (At 150, the EPA deems air pollutant levels unhealthy for everyone exposed).
Toxic Release Inventory (TRI) represents the number of toxic substance pounds released, or produced, managed and disposed of in each MSA per year, as reported by the facilities generating them. While the TRI does not indicate these substances find their way into the environment or threaten exposure to humans residing in the area, it does reflect the sheer amount of toxic activity taking place.
Data to calculate the remaining measures came from Sperling’s Best Places (an online research aggregator that collects health and living quality indexes)–the ratings used here were for the MSAs’ water quality and air quality. Lastly, they tallied in data for Superfund sites (uncontrolled or abandoned places where hazardous waste is located, possibly affecting local ecosystems or people). Sperling’s factors in both the number of active sites and the amount of cleanup funding they’re receiving.
Click through to see the top ten least toxic cities, number 1 being the cleanest of the group.