{"id":4672,"date":"2026-03-26T01:49:13","date_gmt":"2026-03-26T01:49:13","guid":{"rendered":"https:\/\/tmbglobal.news\/index.php\/2026\/03\/26\/how-ann-arbors-winter-snowmelt-might-affect-your-health\/"},"modified":"2026-03-26T01:49:17","modified_gmt":"2026-03-26T01:49:17","slug":"how-ann-arbors-winter-snowmelt-might-affect-your-health","status":"publish","type":"post","link":"https:\/\/tmbglobal.news\/index.php\/2026\/03\/26\/how-ann-arbors-winter-snowmelt-might-affect-your-health\/","title":{"rendered":"How Ann Arbor\u2019s winter snowmelt might affect your health"},"content":{"rendered":"<p><\/p>\n<div>\n<p>As temperatures gradually rise above freezing in Ann Arbor, melting snow indicates the end to winter is near. But underneath the slush lining city streets lies months of accumulated urban <a href=\"https:\/\/www.tandfonline.com\/doi\/full\/10.1080\/1573062X.2021.1941138#d1e174\">pollution<\/a>, which is <a href=\"https:\/\/www.mlive.com\/weather\/2026\/02\/why-michigans-sudden-snowmelt-is-triggering-air-quality-alerts.html\">released<\/a> into the air as the snow melts.\u00a0<\/p>\n<p>In an interview with The Michigan Daily, Mark Flanner, associate professor of climate and space sciences and engineering, said snow doesn\u2019t just passively sit on the ground during the winter; it also acts as a sponge, absorbing pollution in the form of particulate matter.\u00a0<\/p>\n<p>\u201cThe snowpack acts as a big storage container for atmospheric pollutants collected throughout the winter,\u201d Flanner said. \u201cFalling snowflakes collect particles and chemicals in the air, and can do so more effectively than raindrops because they have much larger surface area than raindrops.\u201d<\/p>\n<p>That means vehicle exhaust, heavy metals from automobile parts and road salt <a href=\"https:\/\/www.uc.edu\/news\/articles\/2026\/02\/scientists--slushy-snowmelt-isnt-just-a-nuisance.html\">all settle<\/a> into snowbanks along roads and sidewalks. While frozen, these particles remain trapped and attached to ice crystals.\u00a0<\/p>\n<aside class=\"scaip scaip-1    \">\n\t\t<\/aside>\n<p>Kerri Pratt, professor of chemistry and earth and environmental sciences, wrote in an email to The Daily that this buildup is often visible to the naked eye.\u00a0<\/p>\n<p>\u201cPollutants, in the form of gases and atmospheric particulate matter (i.e. particles, PM), fall onto the snow over the winter,\u201d Pratt wrote. \u201cFor example, we can see snow darken from vehicle soot and road dust coating the snow. Most of these pollutants stay on the snow until snowmelt, but some can undergo reactions.\u201d<\/p>\n<p>As snow partially melts during the day and refreezes overnight, crusted layers form. Flanner said, under certain conditions, these layers can break apart and be lifted by wind or traffic, sending microscopic particles back into the atmosphere.\u00a0<\/p>\n<p>\u201cThe dirty layers at the top of the nearly melted snow and on the newly exposed ground become sources of particulate matter entering the atmosphere and degrading air quality,\u201d Flanner said. \u201cWhen there is not much wind to carry the pollution away and mix it with cleaner air, as happened in mid-February, the air quality can become hazardous.\u201d\u00a0<\/p>\n<p>Pratt wrote this phenomenon can help explain the <a href=\"https:\/\/www.wkyc.com\/article\/weather\/weather-blog\/snowmelt-induced-fog\/95-ed27e6ab-db9a-4ca0-824d-403137c1d9c0\"\/>foggy conditions during snowmelt as relative humidity increases. Odors during this period can arise from a mix of factors, including the release of trapped pollutants as well as gases from thawing organic matter and urban runoff.<\/p>\n<aside class=\"scaip scaip-2    \">\n\t\t<\/aside>\n<p>One culprit behind that odor is<a href=\"https:\/\/www.epa.gov\/caddis\/ammonia\"> <\/a>ammonia, which is emitted from sources such as vehicle exhaust, waste and regional agricultural activity. When trapped ammonia is released during snowmelt, it can react with acidic gases produced by vehicle exhaust \u2014 such as nitric and sulfuric acids \u2014 and <a href=\"https:\/\/www.chemguide.uk\/14to16\/acids\/ammonia.html\">form<\/a> ammonium salts. These salts <a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S1352231013003439\">make up<\/a> fine particulate matter in the atmosphere, <a href=\"https:\/\/www.epa.gov\/pm-pollution\/particulate-matter-pm-basics\">small enough<\/a> to enter the lungs and bloodstream. Particulate matter of this size is associated with increased risk of respiratory and cardiovascular diseases. Another set of reactions involves <a href=\"https:\/\/www.epa.gov\/snep\/winter-coming-and-it-tons-salt-our-roads\">road salt<\/a>, which, when spread to de-ice roads, can <a href=\"https:\/\/pubs.acs.org\/doi\/10.1021\/cen-09823-scicon9\">contribute<\/a> to the formation of reactive chlorine-containing compounds under certain atmospheric conditions.\u00a0<\/p>\n<p>Scientists fear global warming might worsen air quality, as warmer temperatures and less snowfall won\u2019t necessarily lead to less pollution. Instead, climate change is expected to <a href=\"https:\/\/glisa.umich.edu\/resources-tools\/climate-impacts\/temperature\/\">increase winter temperature<\/a> variability in the Midwest, leading to <a href=\"https:\/\/journals.ametsoc.org\/view\/journals\/apme\/64\/10\/JAMC-D-24-0190.1.xml\">more frequent freeze-thaw cycles<\/a>.<\/p>\n<p>More frequent freeze-thaw cycles can intensify the concentration of pollutants near the surface of snowbanks and thus create more opportunities for particles to become airborne. In other words, the release of pollutants doesn\u2019t only depend on how much snow falls, but also how variable winter temperatures become.<\/p>\n<p>In <a href=\"https:\/\/www.iqair.com\/us\/usa\/michigan\/ann-arbor\">January<\/a>, Ann Arbor had an average air quality index of 52 and 9.9 micrograms per cubic meter. In February, the city had 15 days above normal AQI \u2014 between zero and 50 \u2014 with a high of 111 on Feb. 15. According to the U.S. <a href=\"https:\/\/www.epa.gov\/pmcourse\/patient-exposure-and-air-quality-index\">Environmental Protection Agency<\/a>, when the AQI falls between 51 and 100, air quality poses risk to unusually sensitive individuals. Between 101 and 150, children and members of sensitive groups, such as those with preexisting heart or lung conditions, may experience health effects.\u00a0<\/p>\n<p>In an interview with The Daily, Dr. Toby Lewis, a pediatric pulmonologist, said low air quality\u00a0presents worsening symptoms for vulnerable patients.\u00a0<\/p>\n<aside class=\"scaip scaip-3    \">\n\t\t<\/aside>\n<p>\u201cFrom a respiratory perspective, we worry most about asthma and (chronic obstructive pulmonary disease) and cardiovascular events, such as heart attack and stroke, but there is a lot of literature about impacts on other conditions as well,\u201d Lewis said.\u00a0<\/p>\n<p>In an interview with The Daily, LSA junior Celina Cookson said she notices her asthma symptoms flare up during freeze-thaw cycles from changes in humidity.<\/p>\n<p>\u201cEvery single time around this time of year, I go to (University Health Service) for some sort of cough, and I have no other symptoms,\u201d Cookson said. \u201cI think it\u2019s also the change in humidity, because when it snows, and then it melts, that changes the humidity too.\u201d\u00a0<\/p>\n<p>In an interview with The Daily, Public Health junior Simran Sinha said snowmelt during the transition period from winter to spring exacerbates her asthma symptoms.<\/p>\n<p>\u201cAs it gets colder, I tend to get sick more and then with walking outside in the cold, traveling on campus, I do tend to get more shortness of breath and need my inhaler more,\u201d Sinha said. \u201cI definitely think the transition from winter to spring \u2014 that exacerbates my asthma more. I also need to use my inhaler more.\u201d<\/p>\n<aside class=\"scaip scaip-4    \">\n\t\t<\/aside>\n<p>Lewis said healthy adults are <a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC9517891\/\">not immune<\/a> either, particularly those who spend long hours outdoors or engage in strenuous activity.\u00a0<\/p>\n<p>\u201cFor otherwise healthy adults, the risks often have to do with degree of exposure,\u201d Lewis said. \u201cIf you work or do a lot of physical activity outside, you have more time outside and being exposed and also tend to be breathing more deeply and faster due to the intensity of your activity \u2014 more breathing outside equals more exposure,\u201d Lewis said.<\/p>\n<p><em>Daily Staff Reporters Emma Spring and Sophia Jayasekera can be reached at <\/em><a href=\"https:\/\/www.michigandaily.com\/news\/research\/whats-in-the-snow-how-ann-arbors-winter-melt-might-affect-your-health\/mailto:sprinemm@umich.edu\"><em>sprinemm@umich.edu<\/em><\/a><em> and <\/em><a href=\"https:\/\/www.michigandaily.com\/news\/research\/whats-in-the-snow-how-ann-arbors-winter-melt-might-affect-your-health\/mailto:sophiaja@umich.edu\"><em>sophiaja@umich.edu<\/em><\/a><em>.<\/em><\/p>\n<aside>\n\t\t<\/aside>\n<p><h3 class=\"jp-relatedposts-headline\"><em>Related articles<\/em><\/h3>\n<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"<p>As temperatures gradually rise above freezing in Ann Arbor, melting snow indicates the end to winter is near. But underneath the slush lining city streets lies months of accumulated urban pollution, which is released into the air as the snow melts.\u00a0 In an interview with The Michigan Daily, Mark Flanner, associate professor of climate and [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":4673,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18],"tags":[86,242,1990,192,4364,3072],"class_list":{"0":"post-4672","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-news","8":"tag-affect","9":"tag-ann","10":"tag-arbors","11":"tag-health","12":"tag-snowmelt","13":"tag-winter"},"_links":{"self":[{"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/posts\/4672","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/comments?post=4672"}],"version-history":[{"count":1,"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/posts\/4672\/revisions"}],"predecessor-version":[{"id":4674,"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/posts\/4672\/revisions\/4674"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/media\/4673"}],"wp:attachment":[{"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/media?parent=4672"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/categories?post=4672"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tmbglobal.news\/index.php\/wp-json\/wp\/v2\/tags?post=4672"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}