Abstract Detail

Bryological and Lichenological Section/ABLS

Leavitt, Steven [1], St. Clair, Larry [2].

Give ‘em a brake:  Assessing the local impact of vehicular traffic on heavy metal accumulation in lichens.

An air quality bio-monitoring program was established in the Flaming Gorge National Recreation Area (NRA) in northeastern Utah and southwestern Wyoming during the summers of 2010 and 2011, including a total of six reference sites. One site – at the Cart Creek Bridge pullout along U.S. Highway 191 – showed elevated levels for Ni, As, and Pb. The Pb concentrations were of particular concern – representing some of the highest values reported for the Intermountain Area. In order to clarify patterns of elevated heavy metal loads along U.S. Highway 191 in the Flaming Gorge NRA, samples of the sensitive indicator species, Xanthoparmelia sp., were collected from 11 locations in 2013, with a particular emphasis on the Cart Creek Bridge area. Subsamples of each collection were then analyzed using ICP technology for 25+ potential pollutant elements. The 2013 samples showed somewhat elevated levels of Ni and As at several sites along Highway 191. Pb levels were within background levels at all sites except for the 6 Cart Creek Bridge sites where levels continued to be elevated but at generally lower concentrations than the 2011 samples. We also detected elevated levels of N at several locations. Overall these data suggest that the source of elevated heavy metals, particularly the Pb at the Cart Creek Bridge site, is most likely related to general vehicular traffic along Highway 191 but with particular input from large trucks coming down a steep grade. Trucks commonly use the Cart Creek Bridge pullout to cool their brakes. It may be that idling diesel engines and overheated brakes are the source of the elevated heavy metals especially Pb. In spite of the elevated levels of heavy metal pollutants, the overall the diversity of lichen species and particularly the number of sensitive indicator species (26!) upslope from the Cart Creek Bridge pullout indicates that heavy metal impact on the lichen community is minimal.  However, these results indicate that lichens do effectively accumulate airborne pollutants – documenting potential air pollution-related problems. 

1 - The Field Museum, Integrative Research Center, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA
2 - Brigham Young University, M. L. Bean Museum, 2103C ML Bean Museum, Provo, UT, 84602, USA

Keywords:
bio-monitoring
lichens
air pollution
indicator
emissions.

Presentation Type: Oral Paper:Papers for Sections
Session: 2
Location: Firs North/Boise Centre
Date: Monday, July 28th, 2014
Time: 11:15 AM
Number: 2013
Abstract ID:82
Candidate for Awards:None