C. Mack Sewell

Assessment of urinary metals following exposure to a large vegetative fire, New Mexico, 2000

Introduction: In May 2000, a vegetative fire burned 47,000 acres in northern New Mexico, including 7500 acres of land administered by the Los Alamos National Laboratory. We evaluated potential human exposures from the fire. Methods: We surveyed two populations (firefighters and the general population) in four cities for urine heavy metal concentrations. Reference concentrations were based on the Third National Health and Nutrition Examination Survey (NHANES III). Multivariate linear regression assessed the association of urinary metal concentrations with smoke exposure. We also performed isotopic analysis of uranium and cesium on a subset of specimens. Results: A total of 92 firefighters and 135 nonfirefighters participated. In both populations, urinary nickel, cesium, chromium, and uranium concentrations were greater than expected compared with NHANES III reference values. No values required immediate medical follow-up. Regression analysis demonstrated that for National Guard members, arsenic and cadmium levels were significantly related to smoke exposure, and for firefighters, cesium and arsenic levels were significantly related to exposure; however, only for cesium in National Guard members was this association in the positive direction. Isotopic analysis demonstrated that the cesium and uranium were naturally occurring. Conclusions: Some people had spot urine metal concentrations above nationally derived reference values, and values for some metals were associated with smoke exposure. These associations had little public health or clinical importance. Studies of exposures resulting from vegetative fires are difficult, and careful consideration should be given to the technical and communication processes at the outset of a fire exposure investigation. Recommendations for future investigations include testing as soon as possible during or after a fire, and early clinical consultation with a medical toxicologist.

L-tryptophan and eosinophilia-myalgia syndrome

L-Tryptophan and Eosinophilia-Myalgia Syndrome Participants Guide Learning Objectives After completing this case study, the participant should be able to: Discuss issues related to rapid establishment of national surveillance for a newly recognized and little understood disorder. Discuss development of case definitions. Describe the elements of design and the advantages and disadvantages of case-control versus cohort studies. Discuss some of the biases that might have affected these studies. Calculate and interpret a relative risk, odds ratio, and attributable risk percent. List and evaluate the criteria for causation.

Hypersensitivity pneumonitis with Mycobacterium avium complex among spa workers.

Abstract Background: The New Mexico Department of Health (NMDOH) investigated the cause of two cases of hypersensitivity pneumonitis (HP) in spa maintenance workers with laboratory confirmed Mycobacterium avium complex (MAC). The investigation occurred in tandem with worker protection and swimming pool regulatory investigations by the New Mexico Environment Department at the spa where the workers were employed. Objectives: The investigation was conducted in order to identify unreported cases, exposure source(s), and to prevent further worker exposure. Methods: NMDOH surveyed 57 spa employees about symptoms and exposures, categorized jobs according to self-reported exposure to water, and computed odds ratios for symptom reporting by exposure category. Environmental isolates from spa water and filter swabs were cultured and compared to patient isolates by the Environmental and Applied Microbiology Team, Centers for Disease Control and Prevention (CDC). Results: Workers with the highest exposure reported more HP-like symptoms (OR = 9·6), as did intermediate exposure workers (OR = 6·5), compared to workers with no aerosolized water exposure. Two of 13 environmental isolates were closely related to one of the patient isolates. Conclusions: Workers were likely exposed during spray cleaning of cartridge filters in a poorly ventilated work space. Recommendations include inhibiting organism growth in spa systems, assuring the use of respiratory protection, and adequately ventilating work spaces where filters and equipment are cleaned.