GUEST BLOG: Low-income counties in NC are more vulnerable to air pollution than wealthier counties

Apr 24, 2018

Where you live matters

By Dorothy Rawleigh, CHES

2018 County Health Rankings Logo

If you reside in one of North Carolina’s poorest counties, there is a greater chance that you are suffering from poorer health than are residents of wealthier counties. This disparate health outcome is further compounded by the fact that people with chronic diseases are often more vulnerable to the health effects of air pollution.

The Robert Wood Johnson Foundation highlights this correlation between low median household incomes and poor health outcomes in its annual County Health Rankings Report. Health rankings are determined by each county’s health outcomes and health factors. Health outcomes are based on measures of premature death, quality of life and the percent of low birth weight newborns. Health factors are based on health behaviors, clinical care, social and economic factors and the physical environment.

Counties with a lower ranking indicate a higher percentage of people living with chronic health conditions like cardiovascular and lung disease, diabetes and obesity.

Robeson County, ranked at No. 100 with the worse health outcomes, also has the state’s fourth-lowest median household income at $31,298. The 10 counties with the lowest health rankings all have median household incomes of less than $35,000. At the other end of the spectrum, the top five wealthiest counties also ranked in the top 10 for health outcomes. Wake County ranked No. 1 and has the state’s highest median income at $70,620.

The higher prevalence of chronic illnesses in the lower income counties results in a greater percentage of the population that is vulnerable to the health effects of air pollution. Ozone and particulate matter air pollution have a greater impact on people with heart or lung disease such as asthma, chronic bronchitis, COPD, emphysema and pulmonary and cardiovascular diseases. When exposed to air pollution these groups will exhibit more sensitivity and experience aggravated symptoms including airway inflammation, decreased lung function, chest pain, palpitations, shortness of breath and fatigue. This sensitivity results in increased medication use, emergency room visits and hospitalizations.

The American Lung Association’s 2017 State of the Air report provides county-level health data that corroborates the findings in the County Health Rankings Report. The State of the Air report shows that the prevalence of COPD, cardiovascular disease and diabetes is higher in the lower median income counties as compared to the higher median income counties. This report gives each county an air quality grade based on data collected from air quality monitors in that county. These grades are only available for 32 of North Carolina’s 100 counties. Of the 10 counties with the lowest county health ranking, only two, Edgecombe and Swain, have air quality monitors. Both of these counties received an air quality grade of “A” while two high health ranking counties, Mecklenburg and Union, received air quality grades of “F” and “C,” respectively. Data collected during the same time period show that the rate of hospital discharges (per 100,000) with a primary diagnosis of asthma was significantly higher for Edgecombe (233.0) and Swain (189.2) compared to Mecklenburg (100.3) and Union (95.6).

It is difficult to draw conclusions about the different rates of asthma discharges and air quality grades when a limited number of counties have air quality monitoring stations. Air quality data can also vary within a county depending on where air quality monitors are placed. Rates of hospital discharges with a primary diagnosis of asthma can be influenced by multiple factors, including access to primary medical homes, controller medications and health insurance.

The Robert Wood Johnson County Health Rankings show that health factors and outcomes vary not only according to where people live but also depending on their racial and ethnic background. The report provides data for whites, blacks and Hispanics on median household income, percent of children living in poverty, premature death and low birth weight. Blacks consistently have the worse outcomes for all measures regardless of the median household income for the county. For example, while 8 percent of babies born in Wake County have a low birth weight, that number jumps to 12 percent for Robeson county babies. This disparity in birth weight is even greater across the state through the lens of race. The statewide rate of white and Hispanic babies born at a low birth weight is 7 percent while for black babies the rate is double that at 14 percent.

Whenever data show that a certain group is experiencing higher rates of poverty, that group tends to have higher rates of chronic diseases and be more vulnerable to the health effects of air pollution.