This article was written by Prof. V. Faye McNeill and her colleague, Dr. Julia Nunes. It gives details on ways to protect yourself and your family from the effects of air pollution. It is the first in a set of articles. The next article in the series will break down air pollution data from across India, demonstrating that most Indians are exposed to unhealthy air for much of the year.
Image: Smog in the Delhi/NCR area. Photo credit: Jesse Rabek.
World Asthma Day reminds us at the AIRE team why we care about clean air. Air pollution is a trigger for asthma. According to the 2017 HEI State of Global Air report, most people on Earth are living with PM2.5 concentrations which the US EPA has labeled as “Unhealthy for Sensitive Groups,” which includes people with asthma. Air Quality has improved enormously in the US, to the benefit of asthmatics and everyone else, since the passing of the Clean Air Act of 1970. The improvements in US air quality are even visible from space. However, India, China, UK, and other nations worldwide are currently facing air quality crises. Cleaning up the air in order to protect public health, while at the same time meeting climate goals, will require a combination of technical insight, policy innovation, and political will.
It’s hot as the Dickens and it’s an air quality action day in the New York city area and in much of the Northeast. Skies are currently blue but the air quality index is in the ‘Unsafe for Sensitive Groups’ range. This plus the super hot weather makes for dangerous conditions for asthmatics, the elderly, and other sensitive groups. So do your best to chill out indoors this weekend!
According to the New York City Department of Health and Mental Hygiene, air quality in NYC is getting better. Here at AIRE, we hypothesized the opposite last summer. Based on a very unscientific survey of our own asthma responses and perceptions of visibility in the city, we suspected that summertime air quality had been on the decline in recent years (2014-2015). To test this hypothesis, summer undergraduate researcher Silvia Vina Lopez gathered Air Quality Index (AQI) data for NYC from 2000-2015, and data on criteria pollutant (SO2, CO, NO2, O3, PM) concentrations from 9 NYSDEC monitoring sites around the five boroughs. Here are some highlights of her findings:
- Overall, air quality has been improving since 2000. Importantly, there has clearly been a steady decrease in the number of “bad air days”. Since 2000, the number of days categorized as “Unhealthy for sensitive groups,” “Unhealthy,” or “Very unhealthy” has been on the decline.
- Since 2008, the number of “Good” air quality days has had an overall upward trend, but there indeed has been a sharp decrease in “Good” days since 2013. Since “Moderate” air quality is also pretty good in the big scheme of things, this trend may be subtle to perceive as you’re walking the streets of NYC unless you have asthma (like us) or think about PM 2.5 a lot (also like us).
To dig deeper into these trends, Silvia investigated the frequency with which each criteria pollutant exceeded the 24 h NAAQS standards. She found that SO2 violations decreased between 2004-2009 and have stayed low. The City attributes this trend to changes in heating oil regulations. On the other hand, the frequency of PM2.5 violations increased over the same time period and has remained elevated since 2009. This value decreased somewhat between 2007-2015, consistent with the data presented in the City’s survey, which covered 2008-2014. However, the average number of PM2.5 violations 2009-2015 was still significantly higher than 2000-2005.
The verdict: air quality in NYC is not bad and getting better in general. However, work needs to be done to reduce PM2.5 violations, and hold on to the gains made between 2008-2014. One possible source of elevated PM2.5 not mentioned in the City’s report is secondary organic aerosol formation: the formation of PM2.5 in situ, due to gas-phase reactions of oxidants and volatile organic compounds (which can be natural or man-made).
Scientists and educators from NASA and UCAR have written a storybook entitled “What’s Up in the Atmosphere? Exploring Colors in the Sky” aimed at elementary school-aged (K-4) children, in which atmospheric aerosols play a starring role. The story follows a group of curious students who, under the guidance of their teacher, investigate the connection between the appearance of the sky and asthma symptoms in their fellow students on a given day. The students in the story (and the readers) learn about atmospheric aerosols in the process. The storybook includes a teachers’ guide with glossary.
Question: An alert on my smartphone told me today is an Ozone Action Day. What is that and how does it affect me? – D.E., New York, NY
Answer: An Ozone Action Day is a day when the concentration of ozone gas in a particular area is predicted to be higher than healthy levels. Ozone Action Days generally coincide with high Air Quality Index days. Ozone is one of the main urban air pollutants that we regulate, due to its potential negative impacts on human health, alone or in combination with other pollutants such as particulate matter. Ozone can irritate the lungs and cause respiratory symptoms, especially in sensitive groups such as children, the elderly, and those with respiratory problems such as asthma or COPD.
On Ozone Action Days it is generally a good idea to avoid exercise outdoors if possible. Children’s outdoor play time should be limited on those days, especially for children with asthma. You can do your part to help keep ozone levels down on Ozone Action Days by taking measures to reduce your emissions of NOx and volatile organic compounds (VOCs): limit electricity use and use of gasoline vehicles.
The AIRE team spends a few weeks every year visiting family in Manila, Philippines. Like many vibrant megacities, Manila suffers from heavy traffic and poor air quality. Starting in Summer 2015, the Philippine government has made real-time air quality monitoring data available from stations around Metro Manila. Interested citizens can look up current PM2.5 levels and compare them to the 24 hour guideline value. We note that the EMB 24 hr guideline value is 75 micrograms/m3, whereas the United States EPA 24-hour average PM2.5 standard is 35 micrograms/m3 (the yearly average standard is 15 micrograms/m3).
This long winter has had the AIRE team thinking about the amount of time we spend indoors, and the air quality there.
– These days, most people spend the vast majority of their time indoors (especially in the winter!). There is therefore high potential for exposure to pollutants indoors, i.e., at home or in the workplace.
– While what we think of as commonplace outdoor pollutants (e.g. car exhaust) may be less prevalent indoors than outdoors, other chemicals such as volatile organic compounds (VOCs) can be present at much higher concentrations indoors. Indoor VOCs may come from many sources including cleaning products, air fresheners, and new furniture. They can harmful to health on their own, or serve as precursors for the formation of aerosol particles.
– You have probably heard about secondhand smoke, which is the exposure of non-smokers by being around smokers. Thirdhand smoke can also be a problem. This occurs when nicotine, tar, and other harmful chemicals in tobacco smoke deposit on indoor surfaces like walls and carpets. People can be directly exposed to these chemicals through contact the surface, or reactions with gases like ozone may cause them to re-enter the gas phase.
We are looking forward to the warmer weather and more time in the fresh air outdoors!
Question: What are the health effects of pollution on humans? – L.I., Miami, FL
Answer: Poor air quality primarily affects the cardiovascular and respiratory systems. According to the EPA, exposure to particulate matter and ozone is associated with aggravated asthma, chronic bronchitis, reduced lung function, irregular heartbeat, heart attack, and premature death in people with heart or lung disease. For more information, see this site on the health effects of air pollution, maintained by Health Canada
Pregunta: Mi hija tiene asma. ¿De qué manera la contaminación del aire afecta a su salud? – M.N., New York, NY
Respuesta: Las personas asmáticas son muy sensibles a los efectos de la contaminación del aire. Al respirar el aire contaminado, esto puede desencadenar o empeorar los síntomas del asma. El ĺndice de Calidad del Aire (AQI) es una medida que nos dice que tan ‘saludable’ es el estado actual del aire que respiramos. El AQI se calcula por los niveles de unas sustancias presentes en el aire, las cuales pueden afectar la salud humana, por ejemplo el ozono y la materia particulada. Un nivel AQI sobre 101 no es saludable para la gente asmática, mientras que para los adultos con un buen estado de salud y sin asma, un nivel de AQI sobre 151 no es saludable.
La Prof. McNeill también tiene asma y en los días con alto AQI, ella no se siente bien y usa más el inhalador. Cuando ella estudiaba en la universidad Caltech, cerca de Los Angeles, la calidad del aire fue muy mala, peor que hoy, y esto la motivó a estudiar la química atmosférica.