Landscape and taxon age are associated with differing patterns of hybridization in two Eucalyptus (Myrtaceae) subgenera.

BACKGROUND AND AIMS: Hybridization is an important evolutionary process that can have a significant impact on natural plant populations. Eucalyptus species are well known for weak reproductive barriers and extensive hybridization within subgenera, but there is little knowledge of whether patterns of hybridization differ among subgenera. Here, we examine eucalypts of Western Australia's Stirling Range to investigate how patterns of hybridization are associated with landscape and taxon age between the two largest Eucalyptus subgenera: Eucalyptus and Symphyomyrtus. In doing so, we tested a hypothesis of OCBIL (old, climatically buffered, infertile landscape) theory that predicts reduced hybridization on older landscapes. METHODS: Single nucleotide polymorphism markers were applied to confirm the hybrid status, parentage and genetic structure of five suspected hybrid combinations for subg. Eucalyptus and three combinations for subg. Symphyomyrtus. KEY RESULTS: Evidence of hybridization was found in all combinations, and parental taxa were identified for most combinations. The older parental taxa assessed within subg. Eucalyptus, which are widespread on old landscapes, were identified as well-defined genetic entities and all hybrids were exclusively F1 hybrids. In addition, many combinations showed evidence of clonality, suggesting that the large number of hybrids recorded from some combinations is the result of long-term clonal spread following a few hybridization events rather than frequent hybridization. In contrast, the species in subg. Symphyomyrtus, which typically occur on younger landscapes and are more recently evolved, showed less distinction among parental taxa, and where hybridization was detected, there were high levels of introgression. CONCLUSIONS: Reduced hybridization in subg. Eucalyptus relative to extensive hybridization in subg. Symphyomyrtus affirmed the hypothesis of reduced hybridization on OCBILs and demonstrate that clade divergence times, landscape age and clonality are important drivers of differing patterns of speciation and hybridization in Eucalyptus.

Uncertainty Analysis of the Core Body Temperature Under Thermal and Physical Stress Using a Three-Dimensional Whole Body Model.

Heat stress experienced by firefighters is a common consequence of extreme firefighting activity. In order to avoid the adverse health conditions due to uncompensable heat stress, the prediction and monitoring of the thermal response of firefighters is critical. Tissue properties, among other parameters, are known to vary between individuals and influence the prediction of thermal response. Further, measurement of tissue properties of each firefighter is not practical. Therefore, in this study, we developed a whole body computational model to evaluate the effect of variability (uncertainty) in tissue parameters on the thermal response of a firefighter during firefighting. Modifications were made to an existing human whole body computational model, developed in our lab, for conducting transient thermal analysis for a firefighting scenario. In conjunction with nominal (baseline) tissue parameters obtained from literature, and physiologic conditions from a firefighting drill, the Pennes bioheat and energy balance equations were solved to obtain the core body temperature of a firefighter. Subsequently, the uncertainty in core body temperature due to variability in the tissue parameters (input parameters), metabolic rate, specific heat, density, and thermal conductivity was computed using the sensitivity coefficient method. On comparing the individual effect of tissue parameters on the uncertainty in core body temperature, the metabolic rate had the highest contribution (within ±0.20°C) followed by specific heat (within ±0.10°C), density (within ±0.07°C), and finally thermal conductivity (within ±0.01 °C). A maximum overall uncertainty of ±0.23 °C in the core body temperature was observed due to the combined uncertainty in the tissue parameters. Thus, the model results can be used to effectively predict a realistic range of thermal response of the firefighters during firefighting or similar activities.

Interaction between ambient pollutant exposure, CD14 (-159) polymorphism and respiratory outcomes among children in Kwazulu-Natal, Durban.

The objective of this study was to determine if the association between exposure to ambient air pollutants such as sulfur dioxide, nitrogen dioxde (NO2), nitrous oxide (NO), and PM10, and variation in lung function measures was modified by genotype. A validated questionnaire was administered to 71 African children to evaluate prevalence of respiratory symptoms. Atopy was evaluated by skin-prick testing and bihourly measures of lung function (spirometry) were collected. Gaseous air pollutant concentrations were monitored continuously. CD14 polymorphism was genotyped and plasma CD14 levels were measured. There was no statistically significant association between the CD14 (159) CT+TT polymorphism with any asthma-related phenotype. There was a significant association between lung function (forced expiratory volume in 1 second intraday variability) and NO2 and NO among participants carrying the CD14 CT/TT genotype for lags 1, 2, and the 5-day average. Similarly, statistically significant gene-pollutant interactions ( p < 0.05) were found with NO and CD14 CT/TT at lag 2 and for the 5-day average. While there was no association with any respiratory phenotype (as determined by symptoms), the CD14 CT/TT genotype appeared to be protective to increased exposure to NO2 and NO.

Levels and sources of volatile organic compounds in homes of children with asthma.

UNLABELLED: Many volatile organic compounds (VOCs) are classified as known or possible carcinogens, irritants, and toxicants, and VOC exposure has been associated with the onset and exacerbation of asthma. This study characterizes VOC levels in 126 homes of children with asthma in Detroit, Michigan, USA. The total target VOC concentration ranged from 14 to 2274 µg/m(3) (mean = 150 µg/m(3); median = 91 µg/m(3)); 56 VOCs were quantified; and d-limonene, toluene, p, m-xylene, and ethyl acetate had the highest concentrations. Based on the potential for adverse health effects, priority VOCs included naphthalene, benzene, 1,4-dichlorobenzene, isopropylbenzene, ethylbenzene, styrene, chloroform, 1,2-dichloroethane, tetrachloroethene, and trichloroethylene. Concentrations varied mostly due to between-residence and seasonal variation. Identified emission sources included cigarette smoking, solvent-related emissions, renovations, household products, and pesticides. The effect of nearby traffic on indoor VOC levels was not distinguished. While concentrations in the Detroit homes were lower than levels found in other North American studies, many homes had elevated VOC levels, including compounds that are known health hazards. Thus, the identification and control of VOC sources are important and prudent, especially for vulnerable individuals. Actions and policies to reduce VOC exposures, for example, sales restrictions, improved product labeling, and consumer education, are recommended. PRACTICAL IMPLICATIONS: Total target VOC concentrations in the Detroit homes ranged from 14 to 2274 lg/m3, generally lower than found in earlier studies. However, a subset of houses had elevated concentrations, and levels of 1,4-dichlorobenzene, naphthalene, and benzene reached levels commensurate with excess individual cancer risks of 10(-2), 10(-3), and 10(-4), respectively. VOC concentrations varied mostly due to between-residence and season effects. The most important sources included cigarette smoking, vehicle-related emissions, building renovation, solvents, household products, and pesticides.

Concentrations and risks of p-dichlorobenzene in indoor and outdoor air.

UNLABELLED: p-dichlorobenzene (PDCB) is a chlorinated volatile organic compound that can be encountered at high concentrations in buildings owing to its use as pest repellent and deodorant. This study characterizes PDCB concentrations in four communities in southeast Michigan. The median concentration outside 145 homes was 0.04 µg/m(3), and the median concentration inside 287 homes was 0.36 µg/m(3). The distribution of indoor concentrations was extremely skewed. For example, 30% of the homes exceeded 0.91 µg/m(3), which corresponds to a cancer risk level of 10(-5) based on the California unit risk estimate, and 4% of homes exceeded 91 µg/m(3), equivalent to a 10(-3) risk level. The single highest measurement was 4100 µg/m(3). Estimates of whole-house emission rates were largely consistent with chamber test results in the literature. Indoor concentrations that exceed a few µg/m(3) indicate the use of PDCB products. PDCB concentrations differed among households and the four cities, suggesting the importance of locational, cultural, and behavioral factors in the use patterns of this chemical. The high PDCB levels found suggest the need for policies and actions to lower exposures, for example, sales or use restrictions, improved labeling, and consumer education. PRACTICAL IMPLICATIONS: Distributions of p-dichlorobenzene concentrations in residences are highly right-skewed, and a subset of houses has very elevated concentrations that are equivalent to an excess cancer risk of 10(-3) or higher based on the California unit risk effect estimate. House-to-house variation is large, reflecting differences in use practices. Stronger policies and educational efforts are needed to eliminate or modify indoor usage practices of this chemical.

Changes in serum fast and slow skeletal troponin I concentration following maximal eccentric contractions.

OBJECTIVES: We tested the hypothesis that fast skeletal muscle troponin I (fsTnI) concentration in serum would increase more than those of slow skeletal muscle troponin I (ssTnI) after eccentric exercise of the elbow flexors using a sensitive blood marker to track fibre specific muscle damage. DESIGN: Observational comparison of response in a single experimental group. METHODS: Eight young men (26.4±6.2 years) performed 210 (35 sets of 6) eccentric contractions of the elbow flexors on an isokinetic dynamometer with one arm. Changes in serum fsTnI and ssTnI concentrations, serum creatine kinase (CK) activity, and maximal voluntary isometric contraction torque (MVIC) before and 1, 2, 3, 4 and 14 days following exercise were analysed by a Student-Newman-Keuls multiple comparison test. The relationship between serum CK activity and fsTnI or ssTnI concentrations was determined using a Pearson's product moment correlation. RESULTS: Significant (P<0.05) decreases in MVIC and increases in serum CK activity and fsTnI were evident after exercise, but ssTnI did not change. The time course of changes in fsTnI was similar to that of CK, peaking at 4 days post-exercise, and the two were highly correlated (r=0.8). CONCLUSIONS: Increases in serum fsTnI concentrations reflect muscle damage, and it seems likely that only fast twitch fibres were damaged by eccentric contractions.

Ambient pollution and respiratory outcomes among schoolchildren in Durban, South Africa.

OBJECTIVE: To examine associations between ambient air pollutants and respiratory outcomes among schoolchildren in Durban, South Africa. METHODS: Primary schools from within each of seven communities in two regions of Durban (the highly industrialised south compared with the non-industrial north) were selected. Children from randomly selected grade 4 classrooms were invited to participate. Standardised interviews, spirometry, methacholine challenge testing and skin-prick testing were conducted. Particulate matter (PM), sulphur dioxide (SO2) and carbon monoxide were monitored at each school, while nitrogen oxides (NOx) and other pollutants were monitored at other sites. RESULTS: SO2 was significantly higher in the south than in the north, while PM concentrations were similar across the city. The prevalence of symptoms consistent with asthma of any severity was 32.1%. Covariate-adjusted prevalences were higher among children from schools in the south than among those from the north for persistent asthma (12.2% v. 9.6 %) and for marked airway hyperreactivity (AHR) (8.1% v. 2.8%), while SO2 resulted in a twofold increased risk of marked AHR (95% confidence interval 0.98 - 4.66; p=0.056). CONCLUSIONS: Schoolchildren from industrially exposed communities experienced higher covariate-adjusted prevalences of persistent asthma and marked AHR than children from communities distant from industrial sources. Our findings are strongly suggestive of industrial pollution-related adverse respiratory health effects among these children.

Nasal cytokine responses to natural colds in asthmatic children.

BACKGROUND: The mechanisms by which viruses induce asthma exacerbations are not well understood. OBJECTIVE: We characterized fluctuations in nasal aspirate cytokines during naturally occurring respiratory viral infections in children with asthma. METHODS: Sixteen children underwent home collections of nasal aspirates when they were without cold symptoms and again during self-reported respiratory illnesses. The presence of viral infection was ascertained by multiplex PCR. Cytokines were measured using multiplex immune assay. mRNA expression for selected markers of viral infection was measured using RT-PCR. A cumulative respiratory symptom score was calculated for each day of measurement. Generalized estimated equations were used to evaluate associations between viral infection and marker elevation, and between marker elevation and symptom score. RESULTS: The 16 patients completed a total of 37 weeks of assessment (15 'well' weeks; 22 self-assessed 'sick' weeks). Viral infections were detected in 3 of the 'well' weeks and 17 of the 'sick' weeks (10 rhinovirus, three coronavirus, two influenza A, two influenza B, two respiratory syncytial virus, one parainfluenza). Compared to virus-negative well weeks, nasal aspirate IFN-γ, CXCL8/IL-8, CXCL10/IP-10, CCL5/RANTES, CCL11/eotaxin-1, CCL2/MCP-1, CCL4/MIP-1ß, CCL7/MCP-3, and CCL20/MIP3α protein levels increased during virus-positive sick weeks. Only a subset of cytokines (IFN-γ, CXCL8, CCL2, CCL4, CCL5, and CCL20) correlated with self-reported respiratory tract symptoms. While many aspirates were dilute and showed no mRNA signal, viral infection significantly increased the number of samples that were positive for IFN-λ1, IFN-λ2/3, TLR3, RIG-I, and IRF7 mRNA. CONCLUSIONS AND CLINICAL RELEVANCE: We conclude that in children with asthma, naturally occurring viral infections apparently induce a robust innate immune response including expression of specific chemokines, IFNs, and IFN-responsive genes.

Sources, concentrations, and risks of naphthalene in indoor and outdoor air.

UNLABELLED: Naphthalene is a ubiquitous pollutant, and very high concentrations are sometimes encountered indoors when this chemical is used as a pest repellent or deodorant. This study describes the distribution and sources of vapor-phase naphthalene concentrations in four communities in southeast Michigan, USA. Outdoors, naphthalene was measured in the communities and at a near-road site. Indoors, naphthalene levels were characterized in 288 suburban and urban homes. The median outdoor concentration was 0.15 µg/m(3), and a modest contribution from rush-hour traffic was noted. The median indoor long-term concentration was 0.89 µg/m(3), but concentrations were extremely skewed and 14% of homes exceeded 3 µg/m(3), the chronic reference concentration for non-cancer effects, 8% exceeded 10 µg/m(3), and levels reached 200 µg/m(3). The typical excess individual lifetime cancer risk was about 10(-4) and reached 10(-2) in some homes. Important sources include naphthalene's use as a pest repellent and deodorant, migration from attached garages and, to lesser extents, cigarette smoke and vehicle emissions. Excessive use as a repellent caused the highest concentrations. Naphthalene presents high risks in a subset of homes, and policies and actions to reduce exposures, for example, sales bans or restrictions, improved labeling, and consumer education, should be considered. PRACTICAL IMPLICATIONS: Long-term average concentrations of naphthalene in most homes fell into the 0.2-1.7 µg/m(3) range reported as representative in earlier studies. The highly skewed distribution of concentrations results in a subset of homes with elevated concentrations and health risks that greatly exceed US EPA and World Health Organization (WHO) guidelines. The most important indoor source is the use of naphthalene as a pest repellant or deodorant; secondary sources include presence of an attached garage, cigarette smoking, and outdoor sources. House-to-house variation was large, reflecting differences among the residences and naphthalene use practices. Stronger policies and educational efforts are needed to eliminate or modify indoor usage practices of this chemical.

Particulate matter concentrations in residences: an intervention study evaluating stand-alone filters and air conditioners.

UNLABELLED: This study, a randomized controlled trial, evaluated the effectiveness of free-standing air filters and window air conditioners (ACs) in 126 low-income households of children with asthma. Households were randomized into a control group, a group receiving a free-standing HEPA filter placed in the child's sleeping area, and a group receiving the filter and a window-mounted AC. Indoor air quality (IAQ) was monitored for week-long periods over three to four seasons. High concentrations of particulate matter (PM) and carbon dioxide were frequently seen. When IAQ was monitored, filters reduced PM levels in the child's bedroom by an average of 50%. Filter use varied greatly among households and declined over time, for example, during weeks when pollutants were monitored, filter use was initially high, averaging 84±27%, but dropped to 63±33% in subsequent seasons. In months when households were not visited, use averaged only 34±30%. Filter effectiveness did not vary in homes with central or room ACs. The study shows that measurements over multiple seasons are needed to characterize air quality and filter performance. The effectiveness of interventions using free-standing air filters depends on occupant behavior, and strategies to ensure filter use should be an integral part of interventions. PRACTICAL IMPLICATIONS: Environmental tobacco smoke (ETS) increased particulate matter (PM) levels by about 14 µg/m3 and was often detected using ETS-specific tracers despite restrictions on smoking in the house as reported on questionnaires administered to caregivers. PM concentrations depended on season, filter usage, relative humidity, air exchange ratios, number of children, outdoor PM levels, sweeping/dusting, and presence of a central air conditioner (AC). Free-standing air filters can be an effective intervention that provides substantial reductions in PM concentrations if the filters are used. However, filter use was variable across the study population and declined over the study duration, and thus strategies are needed to encourage and maintain use of filters. The variability in filter use suggests that exposure misclassification is a potential problem in intervention studies using filters. The installation of a room AC in the bedroom, intended to limit air exchange ratios, along with an air filter, did not lower PM levels more than the filter alone.

Determinants of asthma phenotypes in supermarket bakery workers.

While baker's asthma has been well described, various asthma phenotypes in bakery workers have yet to be characterised. Our study aims to describe the asthma phenotypes in supermarket bakery workers in relation to host risk factors and self-reported exposure to flour dust. A cross-sectional study of 517 supermarket bakery workers in 31 bakeries used a questionnaire, skin prick tests, and specific immunoglobulin E to wheat, rye and fungal alpha-amylase and methacholine challenge testing. The prevalence of probable occupational asthma (OA, 13%) was higher than atopic (6%), nonatopic (6%) and work-aggravated asthma (WAA, 3%) phenotypes. Previous episodes of high exposure to dusts, fumes and vapours causing asthma symptoms were more strongly associated with WAA (OR 5.8, 95% CI 1.7-19.2) than OA (2.8, 1.4-5.5). Work-related ocular-nasal symptoms were significantly associated with WAA (4.3, 1.3-13.8) and OA (3.1, 1.8-5.5). Bakers with OA had an increased odds ratio of reporting adverse reactions to ingested grain products (6.4, 2.0-19.8). OA is the most common phenotype among supermarket bakery workers. Analysis of risk factors contributes to defining clinical phenotypes, which will guide ongoing medical surveillance and clinical management of bakery workers.

PCBs in air, soil and milk in industrialized and urban areas of KwaZulu-Natal, South Africa.

Information regarding polychlorinated biphenyls (PCBs) in environmental media in Africa is limited. This paper presents results of a monitoring program conducted in KwaZulu-Natal Province, South Africa designed to characterize levels, trends and sources of airborne PCBs. Particulate and vapor samples were sampled over the 2004-2005 period at three sites. The total PCB concentration averaged 128+/-47 pgm(-3), and levels were highest in winter. Tri- through hexa-congeners predominated, and the vapor fraction was predominant. Several tetra- through hexa-chlorinated congeners had levels comparable to those at urban sites in the northern hemisphere, but hepta- through deca-congeners resembled levels at background sites. PCB source areas, deduced using spatial and temporal patterns, compositional information and trajectory analyses, likely included local, regional and global sources. Soils at three rural sites showed high PCB concentrations, and milk from a local dairy showed PCB concentrations comparable to USA levels in year 2000.

Functional studies of two novel and two rare mutations in the 21-hydroxylase gene.

Congenital adrenal hyperplasia (CAH) is most commonly due to 21-hydroxylase deficiency and presents with a wide spectrum of clinical manifestations, from prenatal virilization and salt-wasting in the neonatal period to precocious pubarche and late-onset hyperandrogenic symptoms during adulthood. A limited number of mutations account for the majority of all mutated alleles, but a growing number of rare mutations are responsible for the disease in some patients. By sequence analysis of the CYP21A2 gene, we identified two novel (I171N and L446P) and two rare (R341P and R426H) mutations in seven Italian patients with CAH. One of the patients was diagnosed with mild non-classical CAH and was found to be a compound heterozygote (I171N/V281L), while all other patients showed severe phenotypes with latent or manifest salt-wasting. The residual activities measured after expression of the four mutant enzymes in COS-1 cells were all below 1% towards both natural substrates (17-OH-progesterone and progesterone) compared with the wild-type protein. All four mutations are, thus, associated with severe enzyme deficiency and are predicted to cause classic CAH if found in trans with other mutations causing severe enzyme deficiency.

Environmental exposure characterization of fish processing workers.

BACKGROUND: Aerosolization of seafood and subsequent inhalation, during processing is a potential high-risk activity for allergic respiratory disease. OBJECTIVES: To quantify total thoracic particulate, protein concentration and specific fish (pilchard, anchovy) antigen concentrations in fish processing plants; to determine the correlation between these exposure metrics; and to identify the major determinants of variability and the optimal grouping strategies for establishing dose-response relationships for fish antigen exposures. METHODS: Exposure assessments were conducted on randomly selected individuals within each of the identified 'exposure groups' (EGs) in two fish processing factories. Personal time-integrated sampling was conducted with a thoracic fraction sampler and analysed for particulate mass, total protein and specific fish antigens. Exposure metrics were developed on the basis of individually measured exposures and average levels of these personal samples within EGs. The main components of the exposure variability were determined using ANOVA techniques. RESULTS: A total of 198 full-shift personal aerosol samples were collected and analysed. Twenty-two percent of the samples were below the limit of detection (LOD) for pilchard and 23% for anchovy assays. Personal sampling revealed wide variations across EGs in arithmetic mean concentrations of thoracic particulate 0.61 mg m(-3) (range: LOD-11.3), total protein 0.89 microg m(-3) (LOD-11.5), pilchard antigen 150 ng m(-3) (LOD-15 973) and anchovy antigen 552 ng m(-3) (LOD-75 748) levels. The fishmeal loading and bagging sections of both plants showed consistently high thoracic particulate mass (0.811-2.714 mg m(-3)), total protein (0.185-1.855 microg m(-3)), pilchard antigen (538-3288 ng m(-3)) and anchovy antigen (1708-15 431 ng m(-3)). The a priori strategy that grouped workers according to EGs produced reasonably satisfactory summary exposure metric statistics. An alternative grouping strategy based on department revealed comparable elasticity (exposure contrast). While the correlation between the log-transformed thoracic particulate mass and fish antigen concentrations were generally modest (Pearson's r = 0.32-0.35, P < 0.001), a high correlation was found between pilchard and anchovy antigen concentrations (Pearson's r = 0.71, P < 0.001). Models using factory and department grouping strategies accounted for a significant portion of the variability (adjusted r(2) = 0.18, P = 0.043) in pilchard antigen levels. Grouping strategies using a combination of factory and department yielded the highest degree of elasticity for thoracic particulate (0.38) and pilchard antigen (0.42) levels. CONCLUSIONS: Workers involved in bony fish processing are at risk of inhaling aerosols containing pilchard and anchovy fish antigens. Antigen exposures are highest during fishmeal production and bagging. Grouping strategies based on department and factory may provide a more efficient approach than a priori classification of EGs for evaluating fish antigen exposures.

CYP21 mutations in simple virilizing congenital adrenal hyperplasia.

We studied the functional and structural effects of two unique missense mutations in CYP21 found in patients with simple virilizing congenital adrenal hyperplasia. The rare variants L300F and V281G were found in two girls who were each hemizygous for one of the mutations. Functional analysis after expression in COS-1 cells revealed that the mutant enzymes had reduced enzymatic activity for conversion of both 17-hydroxyprogesterone (L300F 9.5%, V281G 3.9% of normal) and progesterone (L300F 4.4%, V281G 3.9% of normal). Both mutant enzymes had an increased degradation in mammalian COS-1 cells compared to the normal protein, although the L300F variant affected the degradation pattern to a greater extent. Our data indicate that the residue L300 is important in maintaining normal structure of the 21-hydroxylase enzyme whereas mutations affecting V281 most likely cause impaired enzyme activity by interfering with a specific function(s) of the protein.

Occupational seafood allergy: a review.

BACKGROUND: Recent years have seen increased levels of production and consumption of seafood, leading to more frequent reporting of allergic reactions in occupational and domestic settings. This review focuses on occupational allergy in the fishing and seafood processing industry. REVIEW: Workers involved in either manual or automated processing of crabs, prawns, mussels, fish, and fishmeal production are commonly exposed to various constituents of seafood. Aerosolisation of seafood and cooking fluid during processing are potential occupational situations that could result in sensitisation through inhalation. There is great variability of aerosol exposure within and among various jobs with reported allergen concentrations ranging from 0.001 to 5.061(microg/m(3)). Occupational dermal exposure occurs as a result of unprotected handling of seafood and its byproducts. Occupational allergies have been reported in workers exposed to arthropods (crustaceans), molluscs, pisces (bony fish) and other agents derived from seafood. The prevalence of occupational asthma ranges from 7% to 36%, and for occupational protein contact dermatitis, from 3% to 11%. These health outcomes are mainly due to high molecular weight proteins in seafood causing an IgE mediated response. Cross reactivity between various species within a major seafood grouping also occurs. Limited evidence from dose-response relations indicate that development of symptoms is related to duration or intensity of exposure. The evidence for atopy as a risk factor for occupational sensitisation and asthma is supportive, whereas evidence for cigarette smoking is limited. Disruption of the intact skin barrier seems to be an important added risk factor for occupational protein contact dermatitis. CONCLUSION: The range of allergic disease associated with occupational exposure to crab is well characterised, whereas for other seafood agents the evidence is somewhat limited. There is a need for further epidemiological studies to better characterise this risk. More detailed characterisation of specific protein antigens in aerosols and associated establishment of dose-response relations for acute and chronic exposure to seafood; the respective roles of skin contact and inhalational exposure in allergic sensitisation and cross reactivity; and the contribution of host associated factors in the development of occupational seafood allergies are important areas for future research.

Is total mass or mass of alveolar-deposited airborne particles of beryllium a better predictor of the prevalence of disease? A preliminary study of a beryllium processing facility.

Cases of chronic beryllium disease (CBD) and beryllium (Be) sensitization continue to be identified among Be industry workers. The currently accepted method for measuring exposure, which involves measuring the total mass of airborne Be per cubic meter, shows an inconsistent dose-response relationship with the prevalence of CBD. This study was conducted to evaluate which Be aerosol characteristics other than total mass may be more informative in understanding the dose-response relationship between exposure to Be and disease. Personal (n = 53) and general (n = 55) area airborne Be samples were collected in five furnace areas at a Be manufacturing facility where prevalence rates of CBD and Be sensitization had been previously studied among 535 employees with significant Be exposure. In the five furnace areas, particle-size specific personal samples and area samples were collected using an Andersen impactor and a microorifice uniform deposit impactor (MOUDI), respectively. The calculated concentrations were expressed in terms of total mass per cubic meter, and in forms of mass, number, and surface area of particles less than 10 microm or less than 3.5 microm mass median aerodynamic diameter per cubic meter that are predicted to deposit in the alveolar region of the lung. Tests for linear trend of the relationships of the various exposure metrics to prevalence of CBD and sensitization demonstrated highly significant associations between mass concentration (MOUDI) of particles less than 10 microm, and less than 3.5 microm, predicted to deposit in the alveolar region of the lung and CBD (p = 0.0004 and 0.000003, respectively) and sensitization (p = 0.025 and 0.003, respectively). However, no statistically significant association was found between these two exposure metrics and personal (Andersen) samples. The number and surface area concentration (MOUDI) of alveolar-deposited particles (less than 10 microm) also showed significant relationships with CBD (p = 0.03 and 0.03, respectively). No other exposure parameters showed significant relationships with CBD or Be sensitization. These results suggest that the concentration of alveolar-deposited particles less than 10 microm or, more particularly, the concentration of alveolar-deposited particles less than 3.5 microm may be a more relevant exposure metric for predicting the incidence of CBD or sensitization than the total mass concentration of airborne Be.

Industrial emergency response training: an assessment of long-term impact of a union-based program.

BACKGROUND: The long-term impact of the United Automobile Workers' (UAW) Industrial Emergency Response Training on health and safety conditions and practices in plants is described. Two strategies are combined in this 24-hour training: the use of peer (worker) trainers and a participant-centered approach, the Small Group Activity Method (SGAM). METHODS: Impact was assessed through a telephone survey of 67 trainees conducted on average 16.8 months post-training. RESULTS: 74% of trainees reported using at least one of the provided written training materials after training. Of those reporting an accident in their facility after training, 88% said it was handled differently because of training. Trainees report that peer-trainers are more knowledgeable and communicate better than do other types of trainers. Trainees also reported that SGAM made training more applicable to their workplace. 98.5% of trainees like the methods utilized. CONCLUSIONS: Worker-trainers and SGAM are effective training methods enhancing the long-term impact of union-based workplace health and safety training programs.

Seafood processing in South Africa: a study of working practices, occupational health services and allergic health problems in the industry.

The work practices, occupational health services and allergic health problems among workplaces which process seafood in Western Cape province of South Africa were examined. A cross-sectional study was conducted among 68 workplaces that were sent a self-administered postal survey questionnaire. Workplaces reporting a high prevalence of work-related symptoms associated with seafood exposure were also inspected. Forty-one (60%) workplaces responded to the questionnaire. The workforce consisted mainly of women (62%) and 31% were seasonal workers. Common seafoods processed were bony fish (76%) and rock lobster (34%). Major work processes involved freezing (71%), cutting (63%) and degutting (58%). Only 45% of workplaces provided an on-site occupational health service and 58% of workplaces conducted medical surveillance. Positive trends were observed between workplace size and activities such as occupational health service provision (P = 0.002), medical surveillance programmes (P = 0.055) and reporting work-related symptoms (P = 0.016). None of the workplaces had industrial hygiene surveillance programmes to evaluate the effects of exposure to seafood. Common work-related symptoms included skin rashes (78%), asthma (7%) and other non-specific allergies (15%). The annual prevalence of work-related skin symptoms reported per workplace was substantially higher for skin (0-100%) than for asthmatic (0-5%) symptoms. The relatively low prevalence of employer-reported asthmatic symptoms, when compared to epidemiological studies using direct investigator assessment of individual health status, suggests likely under-detection. This can be attributed to under-provision and under-development of occupational health surveillance programmes in workplaces with less than 200 workers. This is compounded further by the lack of specific statutory guidelines for the evaluation and control of bio-aerosols in South African workplaces.