In JoVE (1)

Other Publications (2)

Articles by Mark D. Jankowski in JoVE

Other articles by Mark D. Jankowski on PubMed

Summary of Historical Beryllium Uses and Airborne Concentration Levels at Los Alamos National Laboratory

Applied Occupational and Environmental Hygiene. Sep, 2003  |  Pubmed ID: 12909539

Beryllium operations and accompanying medical surveillance of workers at Los Alamos National Laboratory began in the 1940s. In 1999 a Former Workers Medical Surveillance Program that includes screening for chronic beryllium disease was initiated. As part of this program, historical beryllium exposure conditions were reconstructed from archived paper and electronic industrial hygiene data sources to improve understanding of past beryllium uses and airborne concentration levels. Archived industrial hygiene sampling reports indicated beryllium was principally used in technical areas-01 and -03, primarily being machined. Beryllium was also used at 15 other technical areas in activities that ranged from explosives detonation to the manufacture of X-ray windows. A total of 4528 personal breathing zone and area air samples for beryllium, combined for purposes of calculating summary statistics, were identified during the records review phase. The geometric mean airborne beryllium concentration for the period 1949-1989 for all technical areas was 0.04 microg Be/m(3) with 97 percent of all sample below the 2.0 microg Be/m(3) occupational exposure limit (OEL). Average beryllium concentrations per decade were less than 1 microg Be/m(3) and annual geometric mean concentrations in technical area-03, the largest user of beryllium, were generally below 0.1 microg Be/m(3), indicating exposure was generally well-controlled, that is, below the OEL. Typical of many retrospective exposure assessments, not all archived data could be extracted and summarized. Despite this, we report a reasonable summary of potential beryllium uses and airborne concentration levels a worker may have encountered from 1949-1989. These data can be used to more effectively identify former worker populations at potential risk for chronic beryllium disease and to offer these workers screening as part of the Former Worker Medical Surveillance Program, and in the event that a case is diagnosed, help to understand historical exposure conditions.

Testing Independent and Interactive Effects of Corticosterone and Synergized Resmethrin on the Immune Response to West Nile Virus in Chickens

Toxicology. Feb, 2010  |  Pubmed ID: 20096745

Public health agencies utilize aerial insecticides to interrupt an active West Nile virus (WNV) transmission cycle, which may expose WNV-infected birds to these agents. Although resmethrin has been considered benign to birds, no studies have evaluated whether the environmentally employed form of resmethrin with PBO synergist (synergized resmethrin (SR)) can suppress avian immunity to WNV infection and enhance a bird's host competence. Recognizing that wild birds confront toxicological stressors in the context of various physiological states, we exposed four groups (n=9-11) of 9-week-old chickens (Gallus domesticus) to drinking water with either SR (three alternate days at 50 microg/l resmethrin+150 microg/l piperonyl butoxide), CORT (10 days at 20mg/l to induce subacute stress), the combination of SR and CORT, or 0.10% ethanol vehicle coincident with WNV infection. Compared to controls, SR treatment did not magnify but extended viremia by 1 day, and depressed IgG; CORT treatment elevated (mean, 4.26 log(10)PFU/ml) and extended viremia by 2 days, enhanced IgM and IgG, and increased oral virus. The combination of SR and CORT increased the number of chickens that shed oral virus compared to those treated with CORT alone. None of the chickens developed a readily infectious viremia to mosquitoes (none >or=5 log(10)PFU/ml), but viremia in a CORT-exposed chicken was up to 4.95 log(10)PFU/ml. Given that SR is utilized during WNV outbreaks, continued work toward a complete risk assessment of the potential immunotoxic effects of SR is warranted. This would include parameterization of SR exposures with immunological consequences in wild birds using both replicating (in the laboratory) and non-replicating (in the field) antigens. As a start, this study indicates that SR can alter some immunological parameters, but with limited consequences to primary WNV infection outcome, and that elevated CORT mildly enhances SRs immunotoxicity in chickens.

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