Electrostatic dust collectors compared to inhalable samplers for measuring endotoxin concentrations in farm homes.

Paired electrostatic dust collectors (EDCs) and daily, inhalable button samplers (BS) were used concurrently to sample endotoxin in 10 farm homes during 7-day periods in summer and winter. Winter sampling included an optical particle counter (OPC) to measure PM2.5 and PM2.5-10 . Electrostatic dust collectors and BS filters were analyzed for endotoxin using the kinetic chromogenic Limulus amebocyte lysate assay. Optical particle counter particulate matter (PM) data were divided into two PM categories. In summer, geometric mean (geometric standard deviation) endotoxin concentrations were 0.82 EU/m(3) (2.7) measured with the BS and 737 EU/m(2) (1.9) measured with the EDC. Winter values were 0.52 EU/m(3) (3.1) for BS and 538 EU/m(2) (3.0) for EDCs. Seven-day endotoxin values of EDCs were highly correlated with the 7-day BS sampling averages (r = 0.70; P < 0.001). Analysis of variance indicated a 2.4-fold increase in EDC endotoxin concentrations for each unit increase of the ratio of PM2.5 to PM2.5-10 . There was also a significant correlation between BS and EDCs endotoxin concentrations for winter (r = 0.67; P < 0.05) and summer (r = 0.75; P < 0.05). Thus, EDCs sample comparable endotoxin concentrations to BS, making EDCs a feasible, easy to use alternative to BS for endotoxin sampling.

Residential culturable fungi, (1-3, 1-6)-ß-d-glucan, and ergosterol concentrations in dust are not associated with asthma, rhinitis, or eczema diagnoses in children.

Qualitative reporting of home indoor moisture problems predicts respiratory diseases. However, causal agents underlying such qualitative markers remain unknown. In the homes of 198 multiple allergic case children and 202 controls in Sweden, we cultivated culturable fungi by directly plating dust, and quantified (1-3, 1-6)-ß-D-glucan and ergosterol in dust samples from the child's bedroom. We examined the relationship between these fungal agents and degree of parent or inspector-reported home indoor dampness, and microbiological laboratory's mold index. We also compared the concentrations of these agents between multiple allergic cases and healthy controls, as well as IgE-sensitization among cases. The concentrations of culturable fungal agents were comparable between houses with parent and inspector-reported mold issues and those without. There were no differences in concentrations of the individual or the total summed culturable fungi, (1-3, 1-6)-ß-D-glucan, and ergosterol between the controls and the multiple allergic case children, or individual diagnosis of asthma, rhinitis, or eczema. Culturable fungi, (1-3, 1-6)-ß-D-glucan, and ergosterol in dust were not associated with qualitative markers of indoor dampness or mold or indoor humidity. Furthermore, these agents in dust samples were not associated with any health outcomes in the children.

Assessment of airborne exposures and health in flooded homes undergoing renovation.

UNLABELLED: In June 2008, the Cedar River crested flooding more than 5000 Cedar Rapids homes. Residents whose homes were flooded were invited to participate in this study. Household assessments and resident interviews were conducted between November 2008 and April 2009. We characterized exposures and symptoms experienced by individuals inhabiting 73 flood-damaged homes. Active air sampling and passive electrostatic dust collectors were used to assess exposures to culturable mold, culturable bacteria, fungal spores, inhalable particulate matter (iPM), endotoxin, glucans, allergens, lead, asbestos, radon, carbon dioxide, and carbon monoxide. Wall moisture levels and relative humidity were also measured. Exposures and questionnaire-based health assessments were compared at two levels of remediation, in-progress and completed. Homes with remediation in-progress (N = 24), as compared to the completed homes (N = 49), had significantly higher airborne concentrations of mold, bacteria, iPM, endotoxin, and glucan. Residents of in-progress homes had a significantly higher prevalence of doctor-diagnosed allergies (adjusted OR = 3.08; 95% CI: 1.05, 9.02) and all residents had elevated prevalence of self-reported wheeze (adjusted OR = 3.77; 95% CI: 2.06, 6.92) and prescription medication use for breathing problems (adjusted OR = 1.38; 95% CI: 1.01, 1.88) after the flood as compared to before. Proper post-flood remediation led to improved air quality and lower exposures among residents living in flooded homes. PRACTICAL IMPLICATIONS: The number and severity of floods is on the rise, and health departments need evidence-based information to advise homeowners on recovery after such disasters. Our study suggests that proper remediation of flood-damaged homes can reduce bioaerosols to acceptable levels but exposures are significantly increased while remediation is in-progress leading to an increased burden of allergy and allergic rhinitis.

Contribution of solid fuel, gas combustion, or tobacco smoke to indoor air pollutant concentrations in Irish and Scottish homes.

UNLABELLED: There are limited data describing pollutant levels inside homes that burn solid fuel within developed country settings with most studies describing test conditions or the effect of interventions. This study recruited homes in Ireland and Scotland where open combustion processes take place. Open combustion was classified as coal, peat, or wood fuel burning, use of a gas cooker or stove, or where there is at least one resident smoker. Twenty-four-hour data on airborne concentrations of particulate matter<2.5 µm in size (PM2.5), carbon monoxide (CO), endotoxin in inhalable dust and carbon dioxide (CO2), together with 2-3 week averaged concentrations of nitrogen dioxide (NO2) were collected in 100 houses during the winter and spring of 2009-2010. The geometric mean of the 24-h time-weighted-average (TWA) PM2.5 concentration was highest in homes with resident smokers (99 µg/m3--much higher than the WHO 24-h guidance value of 25 µg/m3). Lower geometric mean 24-h TWA levels were found in homes that burned coal (7 µg/m3) or wood (6 µg/m3) and in homes with gas cookers (7 µg/m3). In peat-burning homes, the average 24-h PM2.5 level recorded was 11 µg/m3. Airborne endotoxin, CO, CO2, and NO2 concentrations were generally within indoor air quality guidance levels. PRACTICAL IMPLICATIONS: Little is known about indoor air quality (IAQ) in homes that burn solid or fossil-derived fuels in economically developed countries. Recent legislative changes have moved to improve IAQ at work and in enclosed public places, but there remains a real need to begin the process of quantifying the health burden that arises from indoor air pollution within domestic environments. This study demonstrates that homes in Scotland and Ireland that burn solid fuels or gas for heating and cooking have concentrations of air pollutants generally within guideline levels. Homes where combustion of cigarettes takes place have much poorer air quality.

Development of a synthetic PCB mixture resembling the average polychlorinated biphenyl profile in Chicago air.

Studies of environmental and toxic effects of polychlorinated biphenyls (PCBs) are ideally performed with PCB mixtures reflecting the composition of environmental PCB profiles to mimic actual effects and to account for complex interactions among individual PCB congeners. Unfortunately, only a few laboratory studies employing synthetic PCB mixtures have been reported, in part because of the challenges associated with the preparation of complex PCB mixtures containing many individual PCB congeners. The objective of this study was to develop a PCB mixture that resembles the average PCB profile recorded from 1996 to 2002 at a satellite station of the Integrated Atmospheric Deposition Network located at the Illinois Institute of Technology (IIT) in Chicago, Illinois, using commercial PCB mixtures. Initial simulations, using published Aroclor profiles, showed that a mixture containing 65% Aroclor 1242 and 35% Aroclor 1254 was a good approximation of the target profile. A synthetic Chicago air mixture (CAM) was prepared by mixing the respective Aroclors in this ratio, followed by GC/MS/MS analysis. Comparison of the PCB profile of the synthetic mixture with the target profile suggests that the synthetic PCB mixture is a good approximation of the average IIT Chicago air profiles (similarity coefficient cos θ = 0.82; average relative percent difference = 84%). The synthetic CAM was also a reasonable approximation of the average of 184 PCB profiles analyzed in 2007 at 37 sites throughout Chicago as part of the University of Iowa Superfund Basic Research Program (isbrp), with a cos θ of 0.70 and an average relative percent difference of 118%. While the CAM and the two Chicago air profiles contained primarily di- to pentachlorobiphenyls, higher chlorinated congeners, including congeners with seven or eight chlorine atoms, were underrepresented in the synthetic CAM. The calculated TCDD toxic equivalency quotients of the synthetic CAM (2.7 ng/mg PCB) and the IIT Chicago air profile (1.6 ng/mg PCB) were comparable, but lower by two orders of magnitude than the isbrp Chicago air profile (865 ng/mg PCB) due to surprisingly high PCB 126 levels in Chicago air. In contrast, the calculated neurotoxic equivalency quotients of the CAM (0.33 mg/mg PCB) and the two Chicago air profiles (0.44 and 0.30 mg/mg PCB, respectively) were similar. This study demonstrates the challenges and methods of creating and characterizing synthetic, environmental mixtures of PCBs.

Early-life co-administration of cockroach allergen and endotoxin augments pulmonary and systemic responses.

BACKGROUND: Environmental exposures to cockroach allergen and endotoxin are recognized epidemiological risk factors for the early development of allergies and asthma in children. Because of this, it is important to examine the role of early-life concurrent inhalation exposures to cockroach allergen and endotoxin in the pathogenesis of allergic airways disease. OBJECTIVE: We examined the effects of repeated concomitant endotoxin and cockroach allergen inhalation on the pulmonary and systemic immune responses of newborn and juvenile mice. METHODS: C3H/HeBFeJ mice were exposed to inhaled endotoxin and cockroach allergen via intranasal instillation from day 2 to 21 after birth, and systemic and pulmonary responses were examined in serum, bronchoalveolar lavage fluid, and lung tissue. RESULTS: Cockroach allergen exposures induced pulmonary eosinophilic inflammation, total and allergen-specific IgE, IgG(1), and IgG(2a) production, and alveolar remodelling. Co-exposures with endotoxin and cockroach allergen significantly increased serum IgE and IgG(1), lung inflammation, and alveolar wall thickness, and decreased airspace volume density. Importantly, compared with exposures with individual substances, the responses to co-exposures were more than additive. CONCLUSIONS: Repeated inhalation exposures of neonatal and juvenile mice to endotoxin and cockroach allergen increased the pulmonary inflammatory and systemic immune responses in a synergistic manner and enhanced alveolar remodelling in the developing lung. These data underscore the importance of evaluating the effect of multiple, concurrent environmental exposures, and of using an experimental model that incorporates clinically relevant timing and route of exposures.

Real-time PCR quantification of Mycobacterium immunogenum in used metalworking fluids.

Rapid detection and quantification of Mycobacterium immunogenum in field samples of metalworking fluids (MWFs) is important for factory fluid surveillance programs. The applicability of the developed DNA extraction and quantitative real-time PCR (qPCR) methods to detect and quantify M. immunogenum in used MWFs was evaluated. Total DNA from these samples was extracted, and M. immunogenum measured by qPCR by comparison with a standard curve derived from plasmid vectors. PCR counts were compared with bacterial culture counts. PCR counts of M. immunogenum varied from 1.42 x 10(3) to 3.68 x 10(6) cells/mL of MWFs. Recovery of M. immunogenum by bacterial culture varied from 2.5% to 70% of qPCR count in corresponding samples. Quantitative PCR could be used to measure M. immunogenum load in MWF samples with greater sensitivity and shorter processing time than the classic bacterial culture-based approach. The proposed qPCR approach could be routinely used in real-time PCR-equipped laboratories to provide early detection of M. immunogenum and to control proliferation that probably leads to hypersensitivity pneumonitis in exposed workers.

Acute effect of glucan-spiked office dust on nasal and pulmonary inflammation in guinea pigs.

The acute effects of pure inhaled glucan on respiratory inflammation remain inconclusive and not sufficiently examined with regards to the simultaneous interaction of glucan, endotoxin (lipopolysaccharide, LPS), and house dust in airway inflammation. This study aims at determining effects of simultaneous exposure to office dust and glucan on nasal and pulmonary inflammation. This is relevant for humans with occupational exposure in waste handling and farming and buildings with mold problems. Office dust collected from Danish offices was spiked with 1% (1-3)-beta-glucan (curdlan). Guinea pig nasal cavity volume was measured by acoustic rhinometry (AR) and animals were exposed by inhalation for 4 h to curdlan-spiked dust, unspiked dust, purified air (negative controls), or LPS (positive controls). After exposure (+5 h) or the following day (+18 h), measurements were repeated by AR and followed by bronchoalveolar lavage (BAL). Total and differential cell counts, interleukin (IL)-8 in BAL fluid, and change in nasal volume were compared between groups. A 5-10% increase in nasal volume was seen for all groups including clean air except for a significant 5% decrease for spiked-dust inhalation (+18 h). No marked differences were observed in BAL cells or IL-8 except in LPS-exposed controls. The delayed decrease of nasal cavity volume after exposure to glucan spiked dust suggests a slow effect on the upper airways for curdlan and office dust together, though no pulmonary response or direct signs of inflammation were observed. Glucan-spiked office dust exposures produced a delayed nasal subacute congestion in guinea pigs compared to office dust alone, but extrapolated to nasal congestion in humans, paralleling the nasal congestion seen in human volunteers exposed to the same dust, this may not have clinical importance.

Biomonitoring for assessment of organic dust-induced lung inflammation.

Inhalation exposure to particulate matter containing endotoxin (or lipopolysaccharide (LPS)) occurs in a variety of occupations. Nasal lavage and induced sputum have been used to evaluate lung inflammation resulting from such exposures. Whole blood assay (WBA) measures cytokine production of leukocytes after ex vivo stimulation with LPS. The present study examined the effectiveness of WBA for evaluating inflammatory responses and susceptibility. C3HeB/FEJ mice were tolerised by LPS injection or sham tolerised with saline. Animals then inhaled either swine barn dust extract containing endotoxin or saline. Bronchoalveolar lavage (BAL) fluid was assayed for leukocyte counts and pro-inflammatory cytokines (interleukin-6, tumour necrosis factor-alpha). Whole blood was stimulated with 10 or 100 ng.mL(-1) of LPS, incubated for 5 or 18 h and assayed for cytokines. Barn dust-exposed groups revealed significantly higher total cells, neutrophils and cytokines in BAL compared with saline-exposed groups. Animals tolerised to LPS and exposed to barn dust demonstrated lower cellular and cytokine BAL responses. Similarly, WBA yielded significantly elevated cytokines with barn dust exposure and reduced responses with tolerisation. This study demonstrates the efficacy of whole blood assay as a biomarker of inhalation exposure to inflammatory agents and its use for assessing susceptibility to organic dust-induced lung inflammation.

Educational intervention to control cockroach allergen exposure in the homes of hispanic children in Los Angeles: results of the La Casa study.

BACKGROUND: Cockroach allergy is common among inner city children with asthma, and exposure to cockroach allergen is associated with more severe disease. However, there has been little evaluation of educational approaches for controlling cockroach infestations and reducing allergen exposure. OBJECTIVE: An educational intervention to reduce cockroach allergen exposure in the homes of Hispanic children in Los Angeles was implemented and evaluated. METHODS: Caretakers of 150 children with asthma were randomly assigned to an in-home intervention or comparison group. In the intervention group, peer health educators trained the caretaker to control cockroaches by reducing harbourage and access to food and by applying boric acid, and to reduce allergen exposure by cleaning. Allergen impermeable covers were placed on the child's mattress and pillows. Knowledge, reported and observed behaviour, cockroach counts, and cockroach allergen (Bla g 1) in dust samples from the kitchen and the child's bedding were assessed at study entry and at follow-up 4 months later. RESULTS: There was improvement in knowledge and in observed and reported behaviour hypothesized to be associated with cockroach control. The geometric mean cockroach number in the intervention homes at the follow-up visit was 60% lower than in the non-intervention homes (95% confidence interval (CI) 14%, 81%). Geometric mean total cockroach allergen collected from the child's bedding was 64% lower in the intervention group (95% CI 12%, 85%). In homes with heavier initial cockroach infestation, there was a larger reduction in total kitchen dust allergen and concentration associated with the intervention than in homes with fewer initial cockroaches. CONCLUSIONS: We conclude that reduction in number of cockroaches and in total allergen in bedding dust can be achieved by caretakers of asthmatic children following a single home educational intervention by peer educators.

Comparison of endotoxin exposure assessment by bioaerosol impinger and filter-sampling methods.

Environmental assessment data collected in two prior occupational hygiene studies of swine barns and sawmills allowed the comparison of concurrent, triplicate, side-by-side endotoxin measurements using air sampling filters and bioaerosol impingers. Endotoxin concentrations in impinger solutions and filter eluates were assayed using the Limulus amebocyte lysate assay. In sawmills, impinger sampling yielded significantly higher endotoxin concentration measurements and lower variances than filter sampling with IOM inhalable dust samplers. Analysis of variance for repeated measures showed that this association remained after controlling for other factors such as replicate, sawmill, sawmill operation, wood type, and interaction terms. Endotoxin concentrations in the swine barns were 10-fold higher on average than in sawmills. These samples demonstrated comparable endotoxin concentration estimates for impinger and filter methods although the variability was lower using the impinger method. In both occupational settings, side-by-side replicates were more uniform for the impinger samples than for the filter samples. This study demonstrates that impinger sampling is an acceptable method for quantitation of area endotoxin concentrations. Further, when sampling is performed with impingers for airborne microorganism quantitation, these same impinger solutions can yield valid endotoxin exposure estimates, negating the need for additional filter sampling.

Endotoxin responsiveness and subchronic grain dust-induced airway disease.

Endotoxin is one of the principal components of grain dust that causes acute reversible airflow obstruction and airway inflammation. To determine whether endotoxin responsiveness influences the development of chronic grain dust-induced airway disease, physiological and airway inflammation remodeling parameters were evaluated after an 8-wk exposure to corn dust extract (CDE) and again after a 4-wk recovery period in a strain of mice sensitive to (C3H/HeBFeJ) and one resistant to (C3H/HeJ) endotoxin. After the CDE exposure, both strains of mice had equal airway hyperreactivity to a methacholine challenge; however, airway hyperreactivity persisted only in the C3H/HeBFeJ mice after the recovery period. Only the C3H/HeBFeJ mice showed significant inflammation of the lower airway after the 8-wk exposure to CDE. After the recovery period, this inflammatory response completely resolved. Lung stereological measurements indicate that an 8-wk exposure to CDE resulted in persistent expansion of the airway submucosal cross-sectional area only in the C3H/HeBFeJ mice. Collagen type III and an influx of cells into the subepithelial area participated in the expansion of the submucosa. Our findings demonstrate that subchronic inhalation of grain dust extract results in the development of chronic airway disease only in mice sensitive to endotoxin but not in mice that are genetically hyporesponsive to endotoxin, suggesting that endotoxin is important in the development of chronic airway disease.

Indoor environmental quality in six commercial office buildings in the midwest United States.

The aims of this study were to characterize physical, mechanical, and environmental factors influencing indoor environmental quality (IEQ) in commercial office buildings; document occupant perceptions and psychosocial attributes; and evaluate relationships among these parameters. Six large office buildings in metropolitan areas were selected in Iowa, Minnesota, and Nebraska. Comprehensive sampling was conducted over one week in each building, during all four seasons. This paper presents the study methods and selected results from the first round of sampling (November 1996 to April 1997). Air flow and recirculation rates were quite variable, with the proportion of outdoor air provided to occupants ranging from 10 to 79 CFM/person. Carbon dioxide, carbon monoxide, and temperature were within ranges anticipated for nonproblem buildings. Relative humidity was low, ranging from 11.7 to 24.0 percent. Indoor geometric mean concentrations of total volatile organic compounds (TVOCs) ranged from 73 to 235 microg/m3. The most prevalent compounds included xylene, toluene, 2-propanol, limonene, and heptane. Geometric mean formaldehyde concentrations ranged from 1.7 to 13.3 microg/m3, and mean acetaldehyde levels ranged from <3.0 to 7.5 microg/m3. Airborne concentrations of culturable bacteria and fungi were low, with no samples exceeding 150 CFU/m3. Total (direct count) bioaerosols were more variable, ranging from 5010 to 10,700 organisms/m3. Geometric mean endotoxin concentrations ranged from 0.5 to 3.0 EU/m3. Respirable particulates (PM10) were low (14 to 36 microg/m3). Noise levels ranged from 48 to 56 dBA, with mean light values ranging from 200 to 420 lux. Environmental parameters were significantly correlated with each other. The prevalence of upper respiratory symptoms (dry eyes, runny nose), central nervous system symptoms (headache, irritability), and musculoskeletal symptoms (pain/stiffness in shoulders/neck) were elevated compared to other studies using similar questionnaires. Importantly, psychosocial factors were significantly related to increased symptoms in females, while environmental factors were more closely correlated with symptoms in males. Endotoxin concentrations were associated with symptoms in both males and females. These data will help to identify and quantify the relative role of factors that contribute to sick building syndrome. The data collected in this study may also be used to evaluate the effectiveness of current building operation practices, and can be used to prioritize allocations of resources for reduction of risk associated with IEQ complaints.

Assessment of particulates and bioaerosols in eastern Canadian sawmills.

The purpose of this study was to quantify and identify the airborne contamination in eastern Canadian sawmills. Seventeen sawmills were chosen to cover a wide range of size, geographic distribution, and wood species processed. Within each sawmill different work sites (debarking, sawing, sorting, or planing) were studied separately. Area sampling was performed for exposure assessment. Microbial contaminants were assessed with all-glass impingers 30 and six-stage Andersen microbial samplers; appropriate selective media and culture conditions for bacteria, thermophilic actinomycetes, molds, and yeasts were used. Inhalable dust, endotoxins, temperature, and humidity also were measured. Penicillium species were the most predominant molds with up to 40 different Penicillium species identified. Debarking was the working site most highly contaminated by molds, bacteria, and endotoxins (p=0.0001). At this working site mold levels reached a maximum of 1.5 x 10(6) CFU/m3, whereas the median values for culturable bacteria and endotoxin were 21,620 CFU/m3 and 1,081 endotoxin units/m3, respectively. Planing sites were the most highly dust contaminated (median: 3.0 mg/m3) (p <0.05). Sawmills of eastern Canada contain airborne biological contaminants that vary between working sites, and their microflora is different from that previously described in European sawmills.

Inhalation toxicology models of endotoxin- and bioaerosol-induced inflammation.

Inhalation toxicology studies in rodents have proven their usefulness for furthering our understanding of the causal agents, mechanisms, and pathology associated with exposures to environmental endotoxins and bioaerosols. Inhalation animal models are used to determine which components of a mixture are the most important toxicants for inducing the observed adverse outcome. They are used to obtain exposure-response relationships for allergens and pro-inflammatory agents to help elucidate disease mechanisms and contribute quantitative data to the risk assessment process. Inhalation models serve as important adjuncts to epidemiology studies and human exposure studies. They are also useful for establishing phenotype in studies of genetic polymorphisms and disease susceptibility and are widely applied for evaluation of safety and efficacy for potential therapeutic agents. In order to produce reliable data, rigorous exposure chamber design, aerosol generation systems, exposure quantitation and experimental protocols must be utilized.

Ehrlichia chaffeensis antibodies in white-tailed deer, Iowa, 1994 and 1996.

Surveillance of 2,277 white-tailed deer for antibodies against Ehrlichia chaffeensis in Iowa showed seropositivity rates of 12.5% in 1994 and 13.9% in 1996. From 1994 to 1996, the estimated number of seropositive deer increased to 54,701 (28%). The increasing deer population and expanding tick distribution may increase risk for human monocytic ehrlichiosis.

Preliminary report on the results of the second phase of a round- robin endotoxin assay study using cotton dust.

In an on-going endotoxin assay study, a two-part interlaboratory endotoxin assay study has been completed. The purpose of the study was to compare the variation in assay results between different laboratories, and, if the variation was high, to see if a common protocol would reduce the variation. In both parts of the study, membrane filters laden with the same approximate amount and type of cotton dust were sent for analysis to laboratories that "routinely" perform endotoxin analyses. First, each of these laboratories performed the analysis using the methodology common to its laboratory. In the second part of the study, membrane filters with cotton dust were again sent to the same laboratories where the analyses were performed as before but with a common extraction protocol. The preliminary results from the first phase of the study have been collected and showed that intra-laboratory variations were small, but large and significant interlaboratory variation was observed. The results were reported elsewhere. The preliminary results from the second part of the study consisting of the data currently collected are presented here. Again, intra-laboratory variations were small, but, also again, large and significant inter-laboratory variation was observed. However, in this part of the study, the range between the highest and lowest average results was narrower than in the first part of the study. Influence of the assay kit type was examined. The variation within assay kit type was small but significant differences in results were observed between assay kit types. The findings suggest that endotoxin concentration in samples can be ranked within laboratories, but not necessarily between laboratories. However, some of the variation between laboratories has been reduced by a common extraction protocol which suggests the possibility of further standardization that may lead to better comparability between laboratories.

Increased levels of markers of microbial exposure in homes with indoor storage of organic household waste.

As part of environmental management policies in Europe, separate collection of organic household waste and nonorganic household waste has become increasingly common. As waste is often stored indoors, this policy might increase microbial exposure in the home environment. In this study we evaluated the association between indoor storage of organic waste and levels of microbial agents in house dust. The levels of bacterial endotoxins, mold beta(1-->3)-glucans, and fungal extracellular polysaccharides (EPS) of Aspergillus and Penicillium species were determined in house dust extracts as markers of microbial exposure. House dust samples were collected in 99 homes in The Netherlands selected on the basis of whether separated organic waste was present in the house. In homes in which separated organic waste was stored indoors for 1 week or more the levels of endotoxin, EPS, and glucan were 3.2-, 7.6-, and 4. 6-fold higher, respectively (all P < 0.05), on both living room and kitchen floors than the levels in homes in which only nonorganic residual waste was stored indoors. Increased levels of endotoxin and EPS were observed, 2.6- and 2.1-fold (P < 0.1), respectively, when separated organic waste was stored indoors for 1 week or less, whereas storage of nonseparated waste indoors had no effect on microbial agent levels (P > 0.2). The presence of textile floor covering was another major determinant of microbial levels (P < 0.05). Our results indicate that increased microbial contaminant levels in homes are associated with indoor storage of separated organic waste. These increased levels might increase the risk of bioaerosol-related respiratory symptoms in susceptible people.

Initial results, reliability, and validity of a mental health survey of Mount Pinatubo disaster victims.

This report presents the initial results of a mental health survey of 351 tribal and non-tribal Mount Pinatubo disaster victims 6 years after they were displaced following the volcanic eruption in the Philippines on June 12, 1991. Mental illness prevalence rates in both Filipino ethnic groups were comparable to those found in a U.S. study using the same assessment instrument. Post-traumatic stress disorder (PTSD; 27.6%) and major depression (14.0%) were the two most frequent diagnoses. Diagnostic test-retest interviewer agreement was good for probable alcohol abuse (kappa = .65, agreement = 97%) and any mood disorder (kappa = .53, agreement = 91%) but was reduced for any anxiety disorder (kappa = .15, agreement = 81%) and separately evaluated PTSD (kappa = .18, agreement = 69%). Diagnostic test-retest agreement was good among typical Filipinos (mean kappa = .66, mean agreement = 93%) but was reduced among tribal aborigines (mean = .30, mean agreement = 86%). Internal consistency of the PTSD rating scale was high within and across both ethnic groups, including total scale (alpha = .91) and DSM-IV Criteria B, C, and D sub-scales (alpha = .80, 81, and .78, respectively). With the exception of probable alcohol abuse, construct and criterion validity was demonstrated among both tribal and non-tribal Filipinos for all classes of psychiatric disorders by comparing diagnostic results with respondents' views of their physical and mental health and level of functional impairment. Overall, DSM-IV mood, anxiety, alcohol use, and PTSDs with adequate reliability and construct and criterion validity were made in this culturally diverse, non-Western, disaster victim population. However, test-retest diagnostic agreement was reduced for anxiety disorders and among aboriginal respondents, and validity was not demonstrated for probable alcohol abuse.