Environmental health

Question

I would like to know why ozone levels are lower indoors than outdoors and why, if indoor air pollution is considered higher than outdoor air pollution, do agencies ask people to stay indoors on high ozone days?

Answer

<P>Greetings!<BR><BR>Thank you for submitting your question to AskNSDL. I apologize for the delay. It appears that our specialists were unable to respond to your question. They are all volunteers, and schedules can be very busy.</P> <P>I searched the NSDL and the Internet for resources that address your topic. I've listed a few results below. I found that "sunlight and hot weather can cause increased levels of ozone outside." For more information, check out the following resources.<BR><BR>The National Science Digital Library (NSDL), <A href=http://nsdl.org">http://nsdl.org</A>, has a new addition in its collections: </P> <P>Air Quality Index (AQI)--AIRNow<BR>"The AQI tells you how clean the air is and whether it will affect your health. EPA, state, and local agencies work together to report current and forecast conditions for ozone and particle pollution. AIRNow forecasts next-day air quality."<BR><A href=http://cfpub.epa.gov/airnow/index.cfm?action=airnow.main">http://cfpub.epa.gov/airnow/index.cfm?action=airnow.main</A></P> <P>Check out AQI's section, "Ozone," <A href=http://cfpub.epa.gov/airnow/index.cfm?action=jump.jump_ozone">http://cfpub.epa.gov/airnow/index.cfm?action=jump.jump_ozone</A>.&nbsp; The article, "Good Up High, Bad Nearby", <A href=http://cfpub.epa.gov/airnow/index.cfm?action=gooduphigh.ozone#1">http://cfpub.epa.gov/airnow/index.cfm?action=gooduphigh.ozone#1</A>, states: </P> <P>"Ground-level or "bad" ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC."</P> <P>North Carolina Dept. of Public Health Topics A-Z: Ozone - This website provides an overview of ozone and how it affects health.<BR><A href=http://www.epi.state.nc.us/epi/oee/ozone/index.html">http://www.epi.state.nc.us/epi/oee/ozone/index.html</A></P> <P>The NC Ozone website has a section called "Indoor Ozone," which discusses indoor ozone levels and the use of ozone-generating air cleaners. <BR><A href=http://www.epi.state.nc.us/epi/oee/ozone/indoor.html">http://www.epi.state.nc.us/epi/oee/ozone/indoor.html</A></P> <P>The California Department of Health Services also publishes Indoor Air Quality (IAQ) Information Sheets on Indoor Ozone.<BR><A href=http://www.dhs.ca.gov/iaq/default.asp?q=IndoorOzone&amp;q2=IAQ%20Information%20Sheets:%20Indoor%20Ozone">http://www.dhs.ca.gov/iaq/default.asp?q=IndoorOzone&amp;q2=IAQ%20Information%20Sheets:%20Indoor%20Ozone</A></P> <P>I hope this information helps you find answers to your questions. If you would still like an answer from one of the AskNSDL experts, please feel free to resubmit your question, and we will do what we can to help. Your library is also a good place for materials on this topic.</P> <P>Best wishes,<BR>Joyce W.<BR>AskNSDL Staff/Virtual Reference Librarian<BR></P> http://cfpub.epa.gov/airnow/index.cfm?action=airnow.main http://cfpub.epa.gov/airnow/index.cfm?action=jump.jump_ozone http://cfpub.epa.gov/airnow/index.cfm?action=gooduphigh.ozone#1 http://www.epi.state.nc.us/epi/oee/ozone/index.html http://www.epi.state.nc.us/epi/oee/ozone/indoor.html http://www.dhs.ca.gov/iaq/default.asp?q=IndoorOzone&q2=IAQ%20Information%20Sheets:%20Indoor%20Ozone indoor ozone<BR>ozone<BR> http://vrd.askvrd.org/services/answerschema.xml