Declining-but persistent-atmospheric contamination in central California from the resuspension of historic leaded gasoline emissions as recorded in the lace lichen (Ramalina menziesii Taylor) from 1892 to 2006.
Abstract: Analyses of lead concentration and isotopic composition of recent and archived samples of the lace lichen (Ramalina menziesii) chronicle more than a century of atmospheric lead contamination in central California. The contamination extends back to our oldest sample from 1892, when lead levels in lichen from the northern reach of the San Francisco Bay estuary were 9-12 microg/g and their isotopic composition corresponded to those of high lead emissions from the Selby smelter (e.g., (206)Pb/(207)Pb = 1.165) that were killing horses in adjacent fields at that time. By the mid-1950s lead isotopic compositions of lichens shifted to the more radiogenic leaded gasoline emissions (e.g., (206)Pb/(207)Pb = 1.18-1.22). Lead concentrations in the lichen peaked at 880 microg/g in 1976, corresponding with the maximum of leaded gasoline emissions in California in the 1970s. After that, lead concentrations in lichen declined to current levels, ranging from 0.2 to 4.7 microg/g. However, isotopic compositions of contemporary samples still correspond to those of previous leaded gasoline emissions in California. This correspondence is consistent with other observations that attest to the persistence of environmental lead contamination from historic industrial emissions in central California.
Publication Date: 2010-06-10 PubMed ID: 20527766DOI: 10.1021/es100246eGoogle Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
- Research Support
- U.S. Gov't
- Non-P.H.S.
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
A study of lace lichen samples taken over a century in central California revealed atmospheric lead contamination, with levels peaking in the 1970s due to emissions from leaded gasoline and declining since, but evidence of historic lead contamination still persisting in the environment.
Overview of the Research
- This study examines the lead concentration and isotopic composition in samples of lace lichen, a type of air plant species known as Ramalina menziesii. These lichens are effective sentinel organisms, acting as reliable detectors of atmospheric contamination, in this case focusing on lead.
- The data collected from this lichen species pertain to a period of over a century, stretching from the late 1800s to the early 2000s, thus providing a comprehensive history of atmospheric lead contamination in the central California region.
Detection of Early Lead Contamination
- Lead contamination was detected in the earliest samples dating back to 1892, with lead levels in the lichen recorded as 9-12 micrograms/gram (µg/g).
- The lead isotopic composition in these early samples matched the isotopic composition of lead emissions from the Selby smelter, a local industry at the time. These emissions were high enough to result in the deaths of horses in nearby fields.
Impact of Leaded Gasoline
- In the mid-20th century, a shift in the isotopic composition of lead in the lichen samples was noticed. The lead isotopes were found to correspond more to those found in leaded gasoline emissions.
- Lead concentrations in the sampled lichen reached alarming levels in the 1970s, peaking at 880 µg/g, reflecting the pinnacle of leaded gasoline emissions in the region at that time.
Persistent Lead Contamination
- While the levels of lead concentration in the lichen samples have shown a declining trend following the 1970s, current levels in samples still ranged from 0.2 to 4.7 µg/g.
- Even with the reduced lead concentrations, the isotopic composition in recent samples corresponded to those of previous emissions from leaded gasoline, indicating a persistent contamination in the environment.
- The findings align with other research demonstrating the long-lasting presence of environmental lead contamination arising from past industrial emissions in the Californian region.
Cite This Article
APA
Flegal AR, Gallon C, Hibdon S, Kuspa ZE, Laporte LF.
(2010).
Declining-but persistent-atmospheric contamination in central California from the resuspension of historic leaded gasoline emissions as recorded in the lace lichen (Ramalina menziesii Taylor) from 1892 to 2006.
Environ Sci Technol, 44(14), 5613-5618.
https://doi.org/10.1021/es100246e Publication
Researcher Affiliations
- WIGS Laboratory, Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, California 95064, USA. flegal@metx.ucsc.edu
MeSH Terms
- Air Pollutants / chemistry
- Atmosphere
- California
- Gasoline / analysis
- Lead / chemistry
- Lichens / metabolism
- Time Factors
- Vehicle Emissions / analysis
Citations
This article has been cited 5 times.- Resongles E, Dietze V, Green DC, Harrison RM, Ochoa-Gonzalez R, Tremper AH, Weiss DJ. Strong evidence for the continued contribution of lead deposited during the 20th century to the atmospheric environment in London of today.. Proc Natl Acad Sci U S A 2021 Jun 29;118(26).
- Filippelli G, Anenberg S, Taylor M, van Geen A, Khreis H. New Approaches to Identifying and Reducing the Global Burden of Disease From Pollution.. Geohealth 2020 Apr;4(4):e2018GH000167.
- Weiss-Penzias PS, Bank MS, Clifford DL, Torregrosa A, Zheng B, Lin W, Wilmers CC. Marine fog inputs appear to increase methylmercury bioaccumulation in a coastal terrestrial food web.. Sci Rep 2019 Nov 26;9(1):17611.
- Barre JP, Deletraz G, Frayret J, Pinaly H, Donard OF, Amouroux D. Approach to spatialize local to long-range atmospheric metal input (Cd, Cu, Hg, Pb) in epiphytic lichens over a meso-scale area (Pyrénées-Atlantiques, southwestern France).. Environ Sci Pollut Res Int 2015 Jun;22(11):8536-48.
- Finkelstein ME, Doak DF, George D, Burnett J, Brandt J, Church M, Grantham J, Smith DR. Lead poisoning and the deceptive recovery of the critically endangered California condor.. Proc Natl Acad Sci U S A 2012 Jul 10;109(28):11449-54.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
