Monitoring of heavy metal concentrations in home outdoor air using moss bags

Environ Pollut. 2011 Apr;159(4):954-62. doi: 10.1016/j.envpol.2010.12.004. Epub 2011 Jan 12.


One monitoring station is insufficient to characterize the high spatial variation of traffic-related heavy metals within cities. We tested moss bags (Hylocomium splendens), deployed in a dense network, for the monitoring of metals in outdoor air and characterized metals' long-term spatial distribution and its determinants in Girona, Spain. Mosses were exposed outside 23 homes for two months; NO₂ was monitored for comparison. Metals were not highly correlated with NO₂ and showed higher spatial variation than NO₂. Regression models explained 61-85% of Cu, Cr, Mo, Pb, Sb, Sn, and Zn and 72% of NO₂ variability. Metals were strongly associated with the number of bus lines in the nearest street. Heavy metals are an alternative traffic-marker to NO₂ given their toxicological relevance, stronger association with local traffic and higher spatial variability. Monitoring heavy metals with mosses is appealing, particularly for long-term exposure assessment, as mosses can remain on site many months without maintenance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / analysis
  • Bryopsida / chemistry*
  • Bryopsida / metabolism
  • Cluster Analysis
  • Environmental Monitoring / methods*
  • Metals, Heavy / analysis*
  • Multivariate Analysis
  • Nitrogen Dioxide / analysis
  • Spain
  • Vehicle Emissions / analysis*


  • Air Pollutants
  • Metals, Heavy
  • Vehicle Emissions
  • Nitrogen Dioxide