{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,20]],"date-time":"2026-05-20T20:18:16Z","timestamp":1779308296020,"version":"3.51.4"},"reference-count":51,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2020,6,17]],"date-time":"2020-06-17T00:00:00Z","timestamp":1592352000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["1737633"],"award-info":[{"award-number":["1737633"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We propose a low-cost passive method for monitoring long-term average levels of light-absorbing carbon air pollution in polluted indoor environments. Building on prior work, the method here estimates the change in reflectance of a passively exposed surface through analysis of digital images. To determine reproducibility and limits of detection, we tested low-cost passive samplers with exposure to kerosene smoke in the laboratory and to environmental pollution in 20 indoor locations. Preliminary results suggest robust reproducibility (r = 0.99) and limits of detection appropriate for longer-term (~1\u20133 months) monitoring in households that use solid fuels. The results here suggest high precision; further testing involving \u201cgold standard\u201d measurements is needed to investigate accuracy.<\/jats:p>","DOI":"10.3390\/s20123417","type":"journal-article","created":{"date-parts":[[2020,6,17]],"date-time":"2020-06-17T13:11:32Z","timestamp":1592399492000},"page":"3417","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Developing a Low-Cost Passive Method for Long-Term Average Levels of Light-Absorbing Carbon Air Pollution in Polluted Indoor Environments"],"prefix":"10.3390","volume":"20","author":[{"given":"Lara P.","family":"Clark","sequence":"first","affiliation":[{"name":"Department of Civil &amp; Environmental Engineering, University of Washington, Seattle, WA 98195, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0400-6584","authenticated-orcid":false,"given":"V.","family":"Sreekanth","sequence":"additional","affiliation":[{"name":"Department of Civil &amp; Environmental Engineering, University of Washington, Seattle, WA 98195, USA"},{"name":"Center for Study of Science, Technology &amp; Policy, Bengaluru 560094, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1918-8464","authenticated-orcid":false,"given":"Bujin","family":"Bekbulat","sequence":"additional","affiliation":[{"name":"Department of Civil &amp; Environmental Engineering, University of Washington, Seattle, WA 98195, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"Baum","sequence":"additional","affiliation":[{"name":"Axon Engineering LLC, Bellevue, WA 98006, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Songlin","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Civil &amp; Environmental Engineering, University of Washington, Seattle, WA 98195, USA"},{"name":"Astronaut Center of China, Beijing 100094, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7874-5374","authenticated-orcid":false,"given":"Pao","family":"Baylon","sequence":"additional","affiliation":[{"name":"Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Timothy R.","family":"Gould","sequence":"additional","affiliation":[{"name":"Department of Civil &amp; Environmental Engineering, University of Washington, Seattle, WA 98195, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Timothy V.","family":"Larson","sequence":"additional","affiliation":[{"name":"Department of Civil &amp; Environmental Engineering, University of Washington, Seattle, WA 98195, USA"},{"name":"Department of Environmental &amp; Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4058-0313","authenticated-orcid":false,"given":"Edmund Y. W.","family":"Seto","sequence":"additional","affiliation":[{"name":"Department of Environmental &amp; Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chris D.","family":"Space","sequence":"additional","affiliation":[{"name":"Department of Civil &amp; Environmental Engineering, University of Washington, Seattle, WA 98195, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4087-1209","authenticated-orcid":false,"given":"Julian D.","family":"Marshall","sequence":"additional","affiliation":[{"name":"Department of Civil &amp; Environmental Engineering, University of Washington, Seattle, WA 98195, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,6,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1345","DOI":"10.1016\/S0140-6736(17)32366-8","article-title":"Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990\u20132016: A systematic analysis for the Global Burden of Disease Study 2016","volume":"390","author":"Gakidou","year":"2017","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3944","DOI":"10.1021\/es304942e","article-title":"Cleaner cooking solutions to achieve health, climate, and economic cobenefits","volume":"47","author":"Anenberg","year":"2013","journal-title":"Environ. 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