Home - LETGEN
Welcome to LETGEN, the Laboratory of Ecotoxicology and Comparative Genomics in the Biology Department at Chaminade University. We are interested in how air pollutant gasses and particulates may contribute to development of chronic lung diseases. Our work is primarily with cell lines and involves gene expression profiling. We study the effects of ozone, a common component of urban smog as a model air pollutant, and sulfur dioxide and other components of Hawaii's VOG on differentiation and proliferation of cells. Ozone is not a pollutant of particular concern here in Hawaii, but because the levels of ozone are typically low we can study effects without the need for elaborate efforts to reduce background levels. We use qPCR and focused pathway microarray approaches in our work and have developed a significant bioinformatics effort as well. Funding for this work has largely been due to generous support from NIH INBRE.
The work is open to undergraduates at Chaminade and we frequently host Hawaii State Science Fair students. Chaminade students have worked on many different projects and generally present their findings at ABRCMS, SACNAS, and other society meetings. Chaminade students should contact Dr. Dohm for opportunities to contribute.
About this site
This site includes links to Dr Dohm's Moodle site for the Biology Department at Chaminade University (Click Teaching button in the navigation menu, or click on this link) and registered access to protocols and databases in use by our LETGEN staff.
The LETGEN site also includes Dr Dohm's blog. The blog contains brief articles about Dr Dohm's research and teaching interests plus technical "how to" odds and ends related to supporting student efforts with their computers in bioinformatics.
Hawai'i air quality
As noted on the Clean Air Branch of the State of Hawaii Department of Health's web page, "[a]t most times and in most places in Hawaii, we enjoy some of the best air quality in the nation." This is, of course, because of the islands location in the middle of the Pacific Ocean and the fact that Trade Winds are the most common kinds of wind patterns over the islands throughout most of the year. And yet, between anthropogenic and natural sources, there are more poor air quality days in Hawaii then one would expect. Hawai'i county in 2008 was the 7th worst U.S. county in terms of number of unhealthy days, affecting mostly in low density populated areas. Even Honolulu, which is ranked among the best metropolitan areas in the country for air quality overall must be noted with poor days, particularly with respect to particulates in the PM2.5 range.
While there are anthropogenic contributors, the most famous point-source villain in the air quality story of Hawaii must be the very active volcano on the Big Island. Kilauea on the Big Island of Hawaii has been in continuous eruption since 1983. Daily emissions may contain about 2000 metric tons of sulfur dioxide and aerosol sulfates, but also include about 1 ton of heavy metals, including lead and mercury.
With Kona winds in winter months, the emissions from Kilauea reach Oahu (e.g. this article from the Honolulu Advertiser in 2004), and the air acquires the typical haze one would normally associate with some U.S. mainland cities like Los Angeles.
Research at LETGEN
Our work has focused on the contributions of heavy metals collected from road-side and dust collections collected from various locations on the islands. We are using gene expression profiling of lung cells to model exposures to investigate effects of volcanic emissions on regulation of cell proliferation and other processes related to respiratory disease.
At right is a Comet assay image and bar chart (mean + SD) of the rat lung cell line L2 (ATCC CCL-149) one hour, four hours, or twenty-four hours after exposure to Air or Ozone (0.2 ppm) for 30 minutes. DNA damage is a well recognized consequence of exposure to ozone and we use this assay to select concentrations and durations of exposure when cell viability is greater than 90% and cells exhibit little DNA damage by 24 hours post exposure.