In a region long affected by pollution, questions such as these get asked: Where is it best to breathe? And where should people consider holding their breath?
"There are bad spots, and there are worse spots," John Graham, senior scientist for the Clean Air Task Force, said of southwestern Pennsylvania, where he has studied particulate pollution levels in work commissioned by the Heinz Endowments.
Levels often are bad region-wide and fail to comply with federal Clean Air Act daily and annual standards.
The air pollution levels overlap with results of a yearlong Pittsburgh Post-Gazette ecological study that shows that 14,636 more people died from heart disease, respiratory disease and lung cancer in 14 counties, from 2000 through 2008, than national mortality rates would predict. Those diseases have been linked to air pollution exposure.
Based on those rates, the Post-Gazette has identified 10 areas in southwestern Pennsylvania where caution is warranted, along with a few places whose mortality rates are among the lowest.
Rankings are based on age-adjusted mortality rates, proximity to major sources of pollution and, in many cases, valley terrain that can cause pollution to accumulate rather than dissipate.
Some places may be no surprise. Others may open eyes.
Are some ranked too high? Too low? Should a place be added or subtracted from the list?
Let the debates begin.
1. Clairton and Allegheny County's Monongahela River Valley.
Communities: North Braddock to Elizabeth Borough and Township and centered in Clairton. Glassport, Lincoln, Liberty, Dravosburg, Duquesne, East Pittsburgh, Homestead, McKeesport and West Mifflin, along with smaller municipalities.
Mortality rates: The 20 Mon Valley communities in this region of Allegheny County experienced 1,406 more deaths than expected, based on national rates.
Major sources of industrial pollution: Eastman Chemical in West Elizabeth; U.S. Steel Corp.'s Clairton Coke Works, Irvin Works in West Mifflin and Edgar Thomson steel mill in North Braddock. The Mon Valley also faces exposure to pollution from the Mitchell and Elrama power plants bordering southern Allegheny County in eastern Washington County.
Other factors: Heavy industry in deep, highly populated valley. Poverty and lifestyle factors could aggravate mortality rates.
2. Cheswick -- and the Allegheny River corridor.
Communities: Cheswick, Tarentum, Brackenridge, East Deer, Springdale Borough and Township, and Harrison Township, along with Arnold, Lower Burrell and New Kensington across the river in Westmoreland County.
Mortality rates: Cheswick's mortality numbers are 87 percent over the national level (167 deaths compared with 89 expected), with the Allegheny River Valley showing high death rates for diseases linked to pollution.
Mortality rates also are higher than national rates in Tarentum, Brackenridge, East Deer, Springdale Borough and Township, and Harrison Township. The valley experienced a nine-year total of 639 deaths over expected rates -- 3,309 actual deaths versus 2,670 expected, or 24 percent over the national level.
Downriver, Verona also has notable mortality numbers -- 261 actual deaths, with only 109 expected, or 140 percent over the national average.
Major sources of industrial pollution: Allegheny Energy's Cheswick power plant and Springdale gas power plant along with the PPG paints plant, all in Springdale Borough; Allegheny Ludlum steel mill in Brackenridge; and Sun Refining in Blawnox directly upwind from Verona.
3. Clearfield -- and central Clearfield County.
Communities: Clearfield and Curwensville boroughs and Pike and Lawrence townships.
Mortality rates: The populated central area of the county experienced 1,226 deaths with only 788 expected, or 439 more deaths than national rates would predict. The rate is 56 percent higher than national levels.
Major sources of industrial pollution: GenOn Energy Inc.'s Shawville power plant in Goshen Township, which lacks a pollution scrubbing system. Clearfield County also sits downwind from pollution generated throughout southwestern Pennsylvania, including Allegheny County. Ten power plants also are poised upwind in neighboring counties.
Other factors: Many Clearfield County residents have wood-burning furnaces, while the county also has a history of coal mining and processing. Interstate 80 runs through the county, producing vehicle emissions. Lack of medical resources, low income and lifestyle factors are other factors that could increase death rates.
4. Beaver Falls -- and the upper Ohio Valley of Beaver County.
Communities: Beaver Falls and 23 communities, mostly along the Ohio River.
Mortality rates: Beaver Falls' 598 deaths were 229 higher than the national average, or 64 percent higher than predicted, 2000 through 2008. Communities bordering the Ohio River showed similar results with 739 deaths above expected rates -- 3,974 actual deaths versus 3,235 expected. The entire region has mortality rates 27 percent higher than the national average.
Major sources of industrial pollution: Power plants along the Ohio River, including FirstEnergy's Bruce Mansfield power plant in Shippingport, along with the AES power plant and smaller Wheaton plant and the Horsehead zinc plant, along with six other sources along the Ohio River. The Armstrong World Industries plant is situated in Beaver Falls. Smokestacks line the Ohio River.
5. Sewickley -- and communities downwind from Neville Island.
Communities: Eighteen communities on the eastern side of the Ohio River near Neville Island, including Bellevue, Avalon, Ben Avon, Kilbuck, Emsworth and Aleppo.
Mortality rates: These communities had 510 more deaths than would be predicted, with 3,618 actual deaths and 3,108 expected. Sewickley's 256 deaths include 79 excess deaths -- 44 percent over the national rate. In second place behind Sewickley sits Bellevue, with a mortality rate 43 percent higher than the national rate, with 405 total deaths and 284 expected -- 121 excess deaths.
Other communities with mortality numbers exceeding expected rates include Coraopolis (122 excess deaths), and West View and Avalon (46 each). Aleppo's rate of 100 deaths with 38 expected -- 62 excess deaths -- is 160 percent higher than national rates would predict.
In all, the 18 communities reflect a mortality rate 16 percent higher than expected.
Major sources of industrial pollution: A chemical plant and Shenango Coke Works on Neville Island.
Other factors: Three communities bordering but upwind from Neville Island -- Stowe, Kennedy and Robinson -- have mortality rates equal to the national rate with 1,044 total deaths compared with 1,045 expected. Sewickley Hills and Sewickley Heights, sitting on the hills overlooking the Allegheny Valley, have rates significantly lower than the national average.
6. Masontown -- and surrounding municipalities.
Communities: Ten Fayette County communities directly east of Hatfield's Ferry power plant and north along the Monongahela River in Greene County (Cumberland Township and Carmichaels).
Mortality rates: The 10 communities experienced 633 more deaths than would be expected -- 3,419 actual deaths compared with an expected total of 2,786. That rate stands 23 percent higher than expected. If Uniontown and surrounding townships of North and South Union are subtracted from the calculation, remaining municipalities still experienced 388 more deaths than expected, or 34 percent higher than the national average.
Major source of industrial pollution: Allegheny Energy's Hatfield's Ferry power plant in Monongahela, Greene County.
Other factors: Fayette County has a notably higher rate of smoking than other counties, along with lifestyle and income factors that could contribute to elevated mortality rates.
7. Greensburg through southwestern Westmoreland County.
Communities: This area encompasses a region from Murrysville to the north, to Hempfield Township to the east and Monessen to the west.
Mortality rates: This area experienced 4,813 deaths, with only 4,351 expected, or 462 over the expected rate, for a mortality rate 11 percent above the national rate.
Major sources of industrial pollution: The semirural character of this region, from the Allegheny County line to Greensburg, includes 22 major sources of pollution including natural gas transport and compressor stations. But the U.S. Environmental Protection Agency's AIRNow.com website also shows that prevailing winds typically carry pollution from the Monongahela Valley into southwestern Westmoreland County and sometimes beyond to Greensburg.
8. Chartiers Creek Valley.
Communities: Bridgeville, Heidelberg and Carnegie.
Mortality rates: All three boroughs have high lung cancer rates, with Heidelberg's rates 140 percent higher than national rates. Heart and respiratory rates also are markedly higher. In total, the three boroughs had mortality rates 36 percent higher than the national average, with 938 deaths compared with 688 expected, for an excess of 249 deaths.
Major sources of pollution: Vehicle pollution from Interstate 79 and the Parkway West, along with the General Electric Consumer Products plant and Universal Stainless steel plant on the outskirts of Bridgeville.
9. Zelienople, Cranberry and northern Allegheny County.
Communities: Zelienople has its own sources of pollution, including BMZ Materials Inc. But it also sits downwind from the Ohio Valley in Beaver County (See No. 4. above). Zelienople's mortality rates are 64 percent higher than expected, with notably high rates in all three disease categories.
But Zelienople represents the northernmost community in a transportation corridor that includes Cranberry in Butler County and Pine and Richland townships in northern Allegheny County, where generally high rates of heart, respiratory and lung cancer deaths are noted.
The corridor of 13 communities, many of them affluent, has experienced 1,949 heart, respiratory and lung cancer deaths with 1,506 expected -- 443 excess deaths. Fifty of those excess deaths occurred in Cranberry, where women face mortality rates that are 20 percent higher for heart disease and 57 percent higher for respiratory disease than national rates would predict.
Major sources of pollution: In addition to pollution from Beaver County sources and several of their own sources, these communities also could be experiencing the impact of vehicle pollution from Route 19, the Pennsylvania Turnpike and Interstate 79, all of which intersect in Cranberry.
10. A tie between Brookville, Jefferson County, and Somerset, Pa.
Several puzzles exist on the total risk maps. Why, for example, are mortality rates so high in central Jefferson County and central Somerset County -- two largely rural counties?
The Brookville area of central Jefferson, along with Summerville Borough and Pine Creek Township, sit due east of the Piney Creek power plant in neighboring Clarion County, which was not included in the Post-Gazette study. The 148 additional deaths over the expected national rate are notable in a more sparsely populated region.
Somerset Township and Borough, the county seat, had 869 deaths with 650 expected, for a total of 219 excess deaths. One potential source of concern: The State Correctional Institution Somerset that's powered by coal and listed by the EPA as a major source of pollution.
Areas with better mortality rates
Several municipalities with mortality rates less than the national average suggest a smaller pollution burden along with socioeconomic factors that reduce disease risk. These include Mt. Lebanon with a rate 10 percent below the national rate and Upper St. Clair, whose mortality rates are 32 percent below national rates.
More upscale areas including South Strabane and Peters in Washington County also show rates below the national average, while South Fayette in western Allegheny County is 28 under the national average. South Fayette is used as a pollution baseline for Allegheny County because of its location on the county's western border that is not immediately downwind from any major source of pollution.
Stowe is 4 percent below, South Versailles is 7 percent below and Churchill is 15 percent below the national average for pollution-related diseases.
While a number of other communities in the region, as Post-Gazette results note, have disease rates less than the national average, the communities with excessive mortality rates outpace those with good rates by a 2-to-1 ratio.