September 2013: Issues Related to Comments Received About "Air Quality 101" Articles
This is the fourteenth article in a series about air quality in general and how it applies to Indiana. This article will discuss issues related to comments I have received regarding this column.
Time out. I have received some comments from two medical doctors who have issues with some of the information in past articles. I thought it would be good to respond to these issues and hopefully bring some harmony into the world.
When I discuss the status of the air quality in areas of the state, I am comparing the measured air quality levels to the national ambient air quality standards (NAAQS) established by the U.S. Environmental Protection Agency (U.S. EPA). They establish these standards to protect people with an adequate margin of safety, including sensitive populations. Health research data is used by U.S. EPA to determine the level of the standards. There is a process where U.S. EPA evaluates each standard every five years and decides whether to retain the standard or modify it. If the medical community has information that indicates that the standards are not adequate, they should pass this information to U.S. EPA.
What Indiana and all of the states must do is keep pollutant levels within the NAAQS, which should protect the people from adverse impacts, if U.S. EPA is setting appropriate standards. Indiana was one of only 19 states that achieved the ozone and fine particle standards in 2009, meaning our air was some of the healthiest in the nation. But some of the other states in that group had lower levels of pollutant, compared to us. Even among states that are meeting standards, the levels of pollutants being picked up on monitors will vary from location to location.
There are several reasons. First is climate. If it rained here more often, we would have less pollution in the air. Rain washes pollutants out of the air and keeps dust down. Second is location. If we were located like Hawaii, for example, where we had clean air blowing in, we would have cleaner air. We located an ozone monitor in eastern Illinois just across the Indiana-Illinois border. It often measures levels near the ozone standard. It is very difficult to meet the standard when levels blowing into a state are near the standard. Third, Indiana has an industrial economy. Indiana supplies a large percentage of goods—including grain, steel, automobiles and other manufactured products—to the entire nation. The manufacturing businesses that operate here have to comply with tight air pollution controls. But even with well controlled sources, we will have more air pollution compared with states that have a lower percentage of industry.
Drawing meaningful conclusions when comparing health data and air quality can be challenging. A few years ago we compared Indiana asthma rates (both adult and childhood) with ozone and fine particle levels. Over the most recent 10 year period, air quality levels of both pollutants had improved. However asthma rates were increasing. When we looked outside Indiana we found similar patterns across the US. One of the problems may be the asthma statistics. These are obtained by the Center for Disease Control (CDC) by making phone calls to selected homes and asking whether anyone in the home has experienced asthma symptoms in the past year. There is no follow-up question about whether there are smokers in the house or whether the family has pets. Both of these factors could significantly impact the results.
We are also interested in lung cancer rates across Indiana. However, good data on smoking rates by county and radon levels by county are necessary to make any sense of the data. These are usually not available.
One of the emails mentioned autism rates in Indiana and the belief that this may be due to air toxics. I have contacted the Department of Health in a search for autism rates by county. The data that I was able to obtain is not of sufficient quality to allow a meaningful study to be done. Due to patient privacy rules, most of the data that I was provided does not provide exact values because the number of cases of autism in a county during a year are small. My point is that there is not a lack of interest in making analyses that would help us determine whether certain chemicals are part of a health problem. Due to the many factors I mentioned above, this work just is not progressing as fast as it should.