Doctors have warned that air pollution increases the risks of dying from COVID-19. This post compares air pollution levels in Italy with the highest European COV-19 mortality with New York State where the largest number of COVID-19 cases have occurred in the US. I am sure the general impression is that New York City air quality is so bad that, if this relationship is true, that similar mortality rates are inevitable but I will show that is not the case.
In an interview Dr. Sucharit Bhakdi, a German microbiology specialist, explains that the reason for the apparent global different mortality rates for COVID-19 may be because of different local situations. He points out Northern Italy and China both have air pollution problems as well as high mortality rates. Consistent with others he suggests that the lungs of individuals in those areas have been chronically injured over decades and this influences the mortality rates.
I compared Italian data with New York data that I had on hand. Italian air quality data are available at the European Environment Agency Italy air pollution country fact sheet website. Air quality data from New York’s monitoring network are available at the New York State Department of Environmental Conservation air quality monitoring website, in their annual reports, and there is an Environmental Protection Agency website that also has the data. Particulate Matter 2.5 (PM2.5 measures particles that are generally 2.5 micrometers or smaller), Particulate 10 (PM10 measures particles that are generally 10 micrometers or smaller), nitrogen dioxide (NO2) and ozone are measured in both jurisdictions. Unfortunately. the readily available summary data for PM10 and ozone data are not directly comparable because the air quality standards are different. New York has only a few monitors for NO2. The pollutant of most concern for health impacts is PM 2.5 because these particles are small enough to get inhaled into the lung. There are seven monitoring sites within New York State with directly comparable PM2.5 data and that have reported data since 1999. The only issue is that those data are not readily available so I have manually extracted these data from annual reports over the years.
The Comparison of Italian Average and Selected New York State Air Monitors Annual Average Air Quality Data table includes Italian and New York PM2.5 annual average measurements that are encouraging. Italian data are downloadable in three categories: Traffic which represents the highest expected levels, suburban/urban background which I assume represents ambient conditions for most people, and rural background which should represent atmospheric concentrations without Italian impacts. The New York data are listed for the Botanical Garden station in New York City, three Upstate cities, a monitoring location on Long Island that is downwind of New York City and two rural background stations.
The Italian traffic impacts site had a PM2.5 annual average of 18.3 µg/m3, the suburban/urban background was 17.2 µg/m3and the rural background was 16.1 µg/m3. The good news is that the monitoring location with the highest observed annual PM2.5 concentrations was at the Botanical Garden monitor in New York City was 8.0 µg/m3 which was less than half the rural Italian average background. Note that in the most recent year there were a total of 23 PM2.5 air monitors operating in New York City. In 2018 the Botanical Garden monitor had an annual average greater than or equal to all but four of the monitors. The highest annual average was 10.4 µg/m3 still well under the Italian rural background. The important thing to note is that all of New York PM2.5 annual averages are smaller than the lowest Italian traffic and suburban/urban background sites since 1999 and the rural background site averages since 2002. There is no question that New York State air quality is substantively better than Italy for PM2.5.
I also list the nitrogen dioxide data. New York NO2 air quality levels are only marginally better than Italy. It is instructive to compare the two pollutants. NO2 primarily gets in the air from the burning of fuel. NO2 forms from emissions from cars, trucks and buses, power plants, and off-road equipment. Most small particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from power plants, industries and automobiles. I suspect the difference between New York and Italian air quality reflects the success of the EPA and New York State air pollution control efforts since 1990. Since 1999 New York power plant sulfur dioxide emissions are down 99% and nitrogen oxides emissions are down 92%. Coupled with concurrent reductions from industrial sources this has been a primary factor for the PM2.5 reductions. I guess that Italian sources have not reduced their emissions as much. On the other hand, New York continues to struggle with the ozone ambient air quality standards in part because nitrogen oxides emissions from the transportation sector have not come down nearly as much. This would explain why the Italian and New York NO2 data don’t differ as much.
I think there is a general perception that New York City air quality is poor. The fact is that while there are still some overall New York issues, the pollution levels have improved significantly. The good news is that if the hypothesis that the COVID-19 mortality rate is related to chronic air pollution levels and that PM2.5 is a good surrogate for that pollution, then these data suggest that factor will not have as much of an effect in New York State in general and New York City either. The PM2.5 concentrations are significantly lower than either Italy and, I would presume, China too.