Methamphetamine residue dermal transfer efficiencies from household surfaces.

Methamphetamine contamination from illegal production operations poses a potential health concern for emergency responders, child protective services, law enforcement, and children living in contaminated structures. The objective of this study was to evaluate dermal transfer efficiencies of methamphetamine from contaminated household surfaces. These transfer efficiencies are lacking for methamphetamine, and would be beneficial for use in exposure models. Surfaces were contaminated using a simulated smoking method in a stainless steel chamber. Household surfaces were carpet, painted drywall, and linoleum. Dermal transfer efficiencies were obtained using cotton gloves for two hand conditions, dry or saliva moistened (wet). In addition, three contact scenarios were evaluated for both hand conditions: one, two, or three contacts with contaminated surfaces. Dermal transfer efficiencies were calculated for both hand conditions and used as inputs in a Stochastic Human Exposure and Dose Simulation model (SHEDS-Multimedia, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, N.C.). Results of this study showed that average dermal transfer efficiencies of methamphetamine ranged from 11% for dry hands to 26% for wet hands. There was a significantly higher wet transfer as compared to dry transfer for all surfaces. For wet hands, dermal transfer depended on surface type with higher transfer from carpet and linoleum as compared to drywall. Based on our estimates of dermal transfer efficiency, a surface contamination clearance level of 1.5 µg/100 cm(2) may not ensure absorbed doses remain below the level associated with adverse health effects in all cases. Additional dermal transfer studies should be performed using skin surrogates that may better predict actual skin transfer.

Potential exposures associated with indoor marijuana growing operations.

We entered a total of 30 indoor marijuana grow operations (IMGO) with law enforcement investigators in order to determine potential exposures to first responders. Samples for airborne fungal spores, volatile organic compounds, carbon dioxide, carbon monoxide, and delta-9-tetrahydrocannabinol (THC) were obtained as well as the identification of chemicals utilized in the IMGO. The chemicals utilized within the IMGOs were primarily pesticides and fertilizers with none showing high toxicity. Although several of the IMGOs had CO2 enrichment processes involving combustion, CO levels were not elevated. THC levels were identified on surfaces within the IMGOs and on the hands of the investigators. Surface levels ranged from <0.1 µg /100 cm(2) to 2000 µg /100 cm(2) with a geometric mean of 0.37 µg /100 cm(2). THC levels on the hands of officers ranged from <0.10 µg /wipe to 2900 µg /wipe with a geometric mean of 15 µg /wipe. These levels were not considered to be elevated to the point of causing a toxic exposure to responders. A total of 407 fungal spore samples were taken using both slit impactor plates and 400-hole impactors. Both methods identified elevated fungal spore levels, especially during the removal of plants from some of the IMGOs. After plant removal, spore counts increased to levels above 50,000 spores/m(3) with one sample over 500,000 spores/m(3). In addition, we found that there was a shift in species between indoor and outdoor samples with Cladosporium sp. the predominant outdoor species and Penicillium sp. the predominant indoor species. We concluded that the potential increase in fungal spore concentrations associated with the investigation and especially removal of the marijuana plants could potentially expose responders to levels of exposure consistent with those associated with mold remediation processes and that respiratory protection is advisable.

Decontamination of clothing and building materials associated with the clandestine production of methamphetamine.

This study was designed to determine how easily methamphetamine can be removed from clothing and building materials, utilizing different cleaning materials and methods. The study also addressed the penetration of methamphetamine into drywall and the ability of paints to encapsulate the methamphetamine on drywall. Clothing and building materials were contaminated in a stainless steel chamber by aerosolizing methamphetamine in a beaker heater. The amount of methamphetamine surface contamination was determined by sampling a grid pattern on the material prior to attempting to clean the materials. After cleaning, the materials were again sampled, and the degree of decontamination noted. We found that household clothing and response gear worn by first responders was easily decontaminated using a household detergent in a household washing machine. A single wash removed over 95% of the methamphetamine from these materials. The study also indicated that methamphetamine-contaminated, smooth non-porous surfaces can be easily cleaned to below detectable levels using only mild cleaners. More porous surfaces such as plywood and drywall were unlikely to be decontaminated to below regulatory levels even with three washes using a mild cleaner. This may be due to methamphetamine penetration into the paint on these surfaces. Evaluation of methamphetamine contamination on drywall indicated that approximately 40% of the methamphetamine was removed using a wipe, while another 60% remained in the paint layer. Stronger cleaners such as those with active ingredients including sodium hypochlorite or quaternary ammonia and commercial decontamination agents were more effective than mild detergent-based cleaners and may reduce methamphetamine contamination to below regulatory levels. Results from the encapsulation studies indicate that sprayed on oil-based paint will encapsulate methamphetamine on drywall and plywood surfaces up to 4.5 months, while latex paints were less effective.

Variability and specificity associated with environmental methamphetamine sampling and analysis.

This study was designed to explore the efficacy of the use of wipe sampling to determine methamphetamine contamination associated with the clandestine manufacture of methamphetamine. Three laboratories were utilized to analyze wipe samples to investigate variability in reported methamphetamine concentration among samples spiked with known amounts of methamphetamine. Different sampling media, surfaces, and solvents were also utilized to determine potential differences in measured methamphetamine concentration due to different wipes, wipe solvents, and wipe contaminants. This study examined rate of false positive detection among blank samples and whether interference with common household substances would create a false positive detection of methamphetamine. Variability between the three labs-using liquid chromatography with mass spectrometry or gas chromatography with mass spectrometry for detection of a known concentration of methamphetamine-resulted in percent differences of 3-30%. Results from wipe sample analysis for methamphetamine, using methanol or isopropanol, showed no significant difference in methamphetamine contamination recovery. Dust and paint contamination on methamphetamine wipe samples with known methamphetamine spike amounts did not affect methamphetamine wipe sample recovery. This study confirmed that either methanol or isopropanol is an appropriate solvent for use in methamphetamine wipe sampling. Dust and paint contamination on wipe samples will not interfere with the wipe sample analysis for methamphetamine. False positive detection for methamphetamine was not observed in any of the blank wipe samples submitted for the study. Finally, this study determined that methamphetamine will not be detected in structures that are truly methamphetamine free at current laboratory limits of quantification.

Risk of chronic beryllium disease by HLA-DPB1 E69 genotype and beryllium exposure in nuclear workers.

RATIONALE: Beryllium sensitization (BeS) and chronic beryllium disease (CBD) are determined by at least one genetic factor, a glutamic acid at position 69 (E69) of the HLA-DPB1 gene, and by exposure to beryllium. The relationship between exposure and the E69 genotype has not been well characterized. OBJECTIVES: The study goal was to define the relationship between beryllium exposure and E69 for CBD and BeS. METHODS: Workers (n = 386) from a U.S. nuclear weapons facility were enrolled into a case-control study (70 BeS, 61 CBD, and 255 control subjects). HLA-DPB1 genotypes were determined by sequence-specific primer-polymerase chain reaction. Beryllium exposures were reconstructed on the basis of worker interviews and historical exposure measurements. MEASUREMENTS AND MAIN RESULTS: Any E69 carriage increased odds for CBD (odds ratio [OR], 7.61; 95% confidence interval [CI], 3.66-15.84) and each unit increase in lifetime weighted average exposure increased the odds for CBD (OR, 2.27; 95% CI, 1.26-4.09). Compared with E69-negative genotypes, a single E69-positive *02 allele increased the odds for BeS (OR, 12.01; 95% CI, 4.28-33.71) and CBD (OR, 3.46; 95% CI, 1.42-8.43). A single non-*02 E69 allele further increased the odds for BeS (OR, 29.54; 95% CI, 10.33-84.53) and CBD (OR, 11.97; 95% CI, 5.12-28.00) and two E69 allele copies conferred the highest odds for BeS (OR, 55.68; 95% CI, 14.80-209.40) and CBD (OR, 22.54; 95% CI, 7.00-72.62). CONCLUSIONS: E69 and beryllium exposure both contribute to the odds of CBD. The increased odds for CBD and BeS due to E69 appear to be differentially distributed by genotype, with non-*02 E69 carriers and E69 homozygotes at higher odds than those with *02 genotypes.

Exposure and genetics increase risk of beryllium sensitisation and chronic beryllium disease in the nuclear weapons industry.

OBJECTIVES: Beryllium sensitisation (BeS) and chronic beryllium disease (CBD) are caused by exposure to beryllium with susceptibility affected by at least one well-studied genetic host factor, a glutamic acid residue at position 69 (E69) of the HLA-DPß chain (DPßE69). However, the nature of the relationship between exposure and carriage of the DPßE69 genotype has not been well studied. The goal of this study was to determine the relationship between DPßE69 and exposure in BeS and CBD. METHODS: Current and former workers (n=181) from a US nuclear weapons production facility, the Y-12 National Security Complex (Oak Ridge, Tennessee, USA), were enrolled in a case-control study including 35 individuals with BeS and 19 with CBD. HLA-DPB1 genotypes were determined by PCR-SSP. Beryllium exposures were assessed through worker interviews and industrial hygiene assessment of work tasks. RESULTS: After removing the confounding effect of potential beryllium exposure at another facility, multivariate models showed a sixfold (OR 6.06, 95% CI 1.96 to 18.7) increased odds for BeS and CBD combined among DPßE69 carriers and a fourfold (OR 3.98, 95% CI 1.43 to 11.0) increased odds for those exposed over an assigned lifetime-weighted average exposure of 0.1 µg/m(3). Those with both risk factors had higher increased odds (OR 24.1, 95% CI 4.77 to 122). CONCLUSION: DPßE69 carriage and high exposure to beryllium appear to contribute individually to the development of BeS and CBD. Among workers at a beryllium-using facility, the magnitude of risk associated with either elevated beryllium exposure or carriage of DPßE69 alone appears to be similar.

Recent chronic beryllium disease in residents surrounding a beryllium facility.

RATIONALE: Between 1948 and 1969, cases of community-acquired chronic beryllium disease (CA-CBD) were reported in neighborhoods surrounding beryllium facilities. Further surveillance was not performed in these communities, and additional cases have not been reported. OBJECTIVES: To increase awareness of recently diagnosed cases of CA-CBD in residents surrounding a beryllium facility. METHODS: Medical records were reviewed from individuals in a community surrounding a beryllium manufacturing facility in Reading, Pennsylvania. Definite cases of CBD required (1) an abnormal beryllium lymphocyte proliferation test in blood or bronchoalveolar lavage and (2) biopsy evidence of granulomatous inflammation. Probable cases of CBD either displayed an abnormal blood test to beryllium and radiographic evidence consistent with disease, or met epidemiologic criteria for CBD based on the Beryllium Case Registry criteria. Cases with occupational or potential paraoccupational exposure were excluded. MEASUREMENTS AND MAIN RESULTS: Sixteen cases of potential community-acquired CBD were evaluated. From these, eight cases of community-acquired CBD were identified (five definite and three probable). The cases' initial year of residence began between 1943 and 1953 and continued until 1956-2001. Six of the eight cases required medical treatment and three of the cases died since diagnosis. CONCLUSIONS: Cases of CBD meeting current immunologic diagnostic criteria and attributable to industry-associated environmental exposure were detected among residents of a community surrounding a beryllium manufacturing facility. Most were diagnosed years after exposure cessation. The frequency and extent of beryllium disease in this community are unknown. We anticipate that not only have cases been misdiagnosed in this community but that more cases of CBD will be diagnosed in the future.

Symptoms experienced by law enforcement personnel during methamphetamine lab investigations.

This study was conducted to determine if law enforcement personnel experience symptoms associated with methamphetamine lab investigation and to assess those factors that may result in more symptoms. A total of 258 standardized, self-administered surveys were distributed to law enforcement personnel attending national/regional training classes, between June 2004-February 2005. Ninety-three percent of the surveys were returned and used to determine symptoms experienced while investigating clandestine methamphetamine labs, as well as the job duties of the respondent and the personal protective equipment used. More than 70% of respondents reported headaches, central nervous system symptoms, respiratory symptoms, sore throat, and other symptoms. Unadjusted and adjusted risk of symptoms was higher for those who investigated more than 30 labs. Other significant risk factors included time spent in the lab, phase of investigation, presence of active chemical processes, and coexistent disease. Respirator use was not independently associated with the likelihood of reporting symptoms. It was concluded that methamphetamine lab investigation is positively associated with symptom reporting in a high percentage of law enforcement personnel involved in these tasks. For most individuals, the reported symptoms were transitory and diminished in a short time, but some individuals reported needing to seek medical attention with symptoms that persisted.

Nontuberculous mycobacteria in aerosol droplets and bulk water samples from therapy pools and hot tubs.

Hot tub exposure has been causally associated with a steroid-responsive, granulomatous lung disease featuring nontuberculous mycobacterial (NTM) growth in both clinical and environmental samples. Little is known regarding prevalence of and risk factors for NTM-contamination and associated illness in these settings. In this study, the frequency of NTM growth and aerosolization in 18 public hot tubs and warm water therapy pools and the factors associated with mycobacterial growth were analyzed. Each site was characterized by water chemistry analysis; a questionnaire on maintenance, disinfection, and water quality; and air and water sampling for quantitative NTM culture. NTM were detected in air or water from 13/18 (72%) sites; a strong correlation was found between the maximum air and water NTM concentrations (rho 0.49, p = 0.04). Use of halogen (chlorine or bromine) disinfection was associated with significantly lower air and water concentrations of NTM compared with disinfection using ultraviolet light and hydrogen peroxide (p = 0.01-0.04). Higher water turnover rates were also associated with lower air and water NTM concentrations (p = 0.02-0.03). These findings suggest that NTM are frequently detectable in the air and water of spas and therapy pools and that particular maintenance and disinfection approaches affect NTM bioaerosol concentrations in these settings.

Characterization of endotoxin and mouse allergen exposures in mouse facilities and research laboratories.

OBJECTIVES: Researchers and technicians who use mice in research are exposed to complex mixtures containing mouse allergen, endotoxin and particulates from animals, bedding and feed. The particle characteristics of these different exposures, and whether they are encountered together or separately, are important to better understand their adjuvant and allergic effects. Endotoxin and mouse allergen are derived from the same animal source, but have different physicochemical attributes. It is not known if airborne exposures to these agents are correlated in the laboratory animal workplace. METHODS: Side-by-side personal and area samples for airborne endotoxin (52), mouse allergen (46) and total particulates (43) were obtained in the animal facility and laboratories of a medical research institution. Animal handlers and researchers reported time spent on work tasks with mice, symptoms upon exposure to mice and mouse sensitization was determined by skin test or RAST. RESULTS: Mean airborne endotoxin exposure was highest during mouse experiments in the animal facility at 960 pg m(-3), peaked at 3125 pg m(-3), and ranged from 46 to 678 pg m(-3) with work in mouse rooms and research labs. Mouse allergen concentrations were highest during direct mouse work and background in research labs (mean 63-68 ng m(-3), range 41-271 ng m(-3)), but were undetectable during mouse research performed under a hood. Endotoxin and mouse allergen concentrations were correlated during direct research with mice and mouse care activities. Particle counts were low, typically < 1 cm(-3), varied widely, and exhibited peaks and valleys during different work tasks. From 80-90% of particles were < 1 microm in aerodynamic diameter during background measurements. The contribution of respirable particles 1-5 microm in size increased to 25-30% during mouse care and mouse research activities, but we found no association between any particle size and endotoxin or mouse allergen concentrations. Animal handlers and researchers in the mouse facility were exposed to the highest daily endotoxin concentrations, whereas researchers working with mice in the mouse facility and in laboratories were exposed to the highest daily mouse allergen concentrations. CONCLUSIONS: These findings suggest that endotoxin and mouse allergen are co-exposures during mouse handling and research, and that control of exposure peaks may be necessary to limit allergic disease in the laboratory animal workplace.

Aerosolized sodium hypochlorite inhibits viability and allergenicity of mold on building materials.

BACKGROUND: Commercial and residential buildings can become contaminated with molds, which may trigger allergic disorders. Mold remediation efforts may require costly replacement of mold-contaminated building materials. Disinfectants that contain dilute sodium hypochlorite can kill mold and are practical to use. Whether they also inhibit mold allergy symptoms is unknown. OBJECTIVE: We tested the hypothesis that sodium hypochlorite-containing spray products kill Aspergillus fumigatus and inhibit A fumigatus allergens. METHODS: A fumigatus was grown on 3 common building construction materials, as well as in solution by conventional laboratory methods. Two sodium hypochlorite-containing household products (diluted bleach and Tilex) were sprayed on the mold-contaminated materials or added to mold in solution and compared with untreated controls. Surface mold and associated debris were mechanically removed from treated and untreated boards. Conidia in the extracted board materials were quantified by light microscopy, examined for morphologic changes by scanning electron microscopy, and cultured for viable mold. Extracts were tested for A fumigatus antigen by ELISA, and for A fumigatus allergen by skin prick testing using extracts prepared from both the boards and the cultured solutions. RESULTS: Both sodium hypochlorite disinfectants killed A fumigatus in solution and on mold-contaminated building materials. Light microscopy and scanning electron microscopy demonstrated changes to the conidial surface. Both dilute bleach and Tilex inhibited A fumigatus recognition by ELISA. Skin testing supported the results of the ELISAs and demonstrated loss of skin test reactivity to the sodium hypochlorite-treated mold solutions in most of the subjects. Of the 4 individuals who had a positive skin test result to mold grown on oriented strand board building material, 3 no longer reacted to extracts from bleach-treated boards. CONCLUSION: Spray application of sodium hypochlorite-containing disinfectants onto mold-contaminated building material kills A fumigatus, modifies the surface characteristics of A fumigatus conidia, reduces recognition of A fumigatus mold by ELISA, and results in loss of skin test reactivity to the treated mold in individuals allergic to A fumigatus.

Cough-generated aerosols of Mycobacterium tuberculosis: a new method to study infectiousness.

The concentration and size distribution of infectious aerosols produced by patients with pulmonary tuberculosis (TB) has never been directly measured. We aimed to assess the feasibility of a method that we developed to collect and quantify culturable cough-generated aerosols of Mycobacterium tuberculosis. Subjects were recruited from a referral hospital and most had multidrug-resistant TB. They coughed into a chamber containing microbial air samplers while cough frequency was measured during two 5-minute sessions. Cough-generated aerosol cultures were positive in 4 of 16 subjects (25%) with smear-positive pulmonary TB. There was a rapid decrease in the cough-generated aerosol cultures within the first 3 weeks of effective treatment. Culture-positive cough aerosols were associated with lack of treatment during the previous week (p = 0.007), and there was a trend in the association with cough frequency (p = 0.08). The size distributions of these aerosols were variable, but most particle sizes were in the respirable range. Quantification of viable cough-generated aerosols is feasible and offers a new approach to study infectiousness and transmission of M. tuberculosis and other airborne pathogens.

Development and piloting of an exposure database and surveillance system for DOE cleanup operations. Department of Energy.

An industrial hygiene exposure database and surveillance system was developed in partnership between National Institute for Occupational Safety and Health (NIOSH)-funded independent investigators and practicing industrial hygienists at the Rocky Flats Environmental Technology Site (RFETS) in Golden, Colo. RFETS is a former U.S. Department of Energy nuclear weapons plant that is now in cleanup phase. This project is presented as a case study in the development of an exposure database and surveillance system in terms that are generalizable to most other industries and work contexts. Steps include gaining organizational support; defining system purpose and scope; defining database elements and coding; planning practical and efficient analysis strategies; incorporating reporting capabilities; and anticipating communication strategies that maximize the probability that surveillance findings will feed back to preventive applications. For each of these topics, the authors describe both general considerations as well as the specific choices made for this system. An important feature of the system is a two-tier task-coding scheme comprising 33 categories of task groups. Examples of grouped analyses of exposure data captured during the system pilot period demonstrate applications to exposure control, medical surveillance, and other preventive measures.

Exposure databases and exposure surveillance: promise and practice.

Based on recent developments in occupational health and a review of industry practices, it is argued that integrated exposure database and surveillance systems hold considerable promise for improving workplace health and safety. A foundation from which to build practical and effective exposure surveillance systems is proposed based on the integration of recent developments in electronic exposure databases, the codification of exposure assessment practice, and the theory and practice of public health surveillance. The merging of parallel, but until now largely separate, efforts in these areas into exposure surveillance systems combines unique strengths from each subdiscipline. The promise of exposure database and surveillance systems, however, is yet to be realized. Exposure surveillance practices in general industry are reviewed based on the published literature as well as an Internet survey of three prominent industrial hygiene e-mail lists. Although the benefits of exposure surveillance are many, relatively few organizations use electronic exposure databases, and even fewer have active exposure surveillance systems. Implementation of exposure databases and surveillance systems can likely be improved by the development of systems that are more responsive to workplace or organizational-level needs. An overview of exposure database software packages provides guidance to readers considering the implementation of commercially available systems. Strategies for improving the implementation of exposure database and surveillance systems are outlined. A companion report in this issue on the development and pilot testing of a workplace-level exposure surveillance system concretely illustrates the application of the conceptual framework proposed.