Associations between evaporative cooling and dust-mite allergens, endotoxins, and β-(1 → 3)-d-glucans in house dust: A study of low-income homes

Indoor Air. 2019 Nov;29(6):1005-1017. doi: 10.1111/ina.12600. Epub 2019 Sep 10.

Abstract

Recent work suggests that evaporative coolers increase the level and diversity of bioaerosols, but this association remains understudied in low-income homes. We conducted a cross-sectional study of metropolitan, low-income homes in Utah with evaporative coolers (n = 20) and central air conditioners (n = 28). Dust samples (N = 147) were collected from four locations in each home and analyzed for dust-mite allergens Der p1 and Der f1, endotoxins, and β-(1 → 3)-d-glucans. In all sample locations combined, Der p1 or Der f1 was significantly higher in evaporative cooler versus central air conditioning homes (OR = 2.29, 95% CI = 1.05-4.98). Endotoxin concentration was significantly higher in evaporative cooler versus central air conditioning homes in furniture (geometric mean (GM) = 8.05 vs 2.85 EU/mg, P < .01) and all samples combined (GM = 3.60 vs 1.29 EU/mg, P = .03). β-(1 → 3)-d-glucan concentration and surface loads were significantly higher in evaporative cooler versus central air conditioning homes in all four sample locations and all samples combined (P < .01). Our study suggests that low-income, evaporative cooled homes have higher levels of immunologically important bioaerosols than central air-conditioned homes in dry climates, warranting studies on health implications and other exposed populations.

Keywords: air conditioning; endotoxin; evaporative cooling; house dust-mite; hygiene hypothesis; β-(1 → 3)-d-glucans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Conditioning / methods*
  • Air Pollution, Indoor / analysis
  • Animals
  • Climate
  • Cross-Sectional Studies
  • Dust / analysis*
  • Endotoxins / analysis*
  • Housing
  • Humans
  • Poverty
  • Pyroglyphidae*
  • Utah
  • Volatilization
  • beta-Glucans / analysis*

Substances

  • Dust
  • Endotoxins
  • beta-1,3-D-glucan
  • beta-Glucans