High Personal Exposure Research Articles

Pollution exposure in the first 3 months post transplant is associated with lower baseline FEV1 and higher CLAD risk

BackgroundExposure to air pollution post lung transplant has been shown to decrease graft and patient survival. This study examines the impact of air pollution exposure in the first 3 months post-transplant on baseline (i.e. highest) forced expiratory volume in 1s (FEV1) achieved and development of chronic lung allograft dysfunction (CLAD). MethodsDouble-lung transplant recipients (n=82) were prospectively enrolled for comprehensive indoor and personal environmental monitoring at 6- and 12-weeks post-transplant and followed for >4 years. Associations between clinical and exposure variables were investigated using an exposomics approach followed by analysis with a Cox Proportional Hazards model. Multivariable analyses were used to examine the impact of air pollution on baseline % predicted FEV1 (defined as the average of the 2 highest values achieved post-transplant) and risk of CLAD. ResultsMultivariable analysis revealed a significant inverse relationship between personal black carbon (BC) levels and baseline % FEV1. The multivariable model indicated that patients with higher-than-median exposure to BC (>350 ng/m3) attained a baseline % FEV1 that was 8.8% lower than those with lower-than-median BC exposure (p = 0.019). Cox proportional hazards model analysis revealed that patients with high personal BC exposure had a 2.4 times higher hazard risk for CLAD than patients with low BC exposure (p = 0.045). ConclusionsHigher personal BC levels during the first 3 months post-transplant decreases baseline FEV1 and doubles the risk of CLAD. Strategies to reduce BC exposure early following lung transplant may help improve lung function and long-term outcomes.

Does real-time and perceived environmental exposure to air pollution and noise affect travel satisfaction? evidence from Beijing, China

Poor air quality and noise pollution have become major environmental risks in urban China. However, the effect of personal exposure to air pollution and noise in various traffic microenvironments on individuals’ daily travel satisfaction has rarely been investigated. Drawing upon real-time data collected using portable sensors and GPS tracking devices in Beijing from December 2017 to February 2018, this paper explores the variations in the co-exposure to real-time air pollution and noise among various transportation modes. It then employs structural equation models to investigate whether and how the objectively measured and subjectively perceived exposure to air pollution and noise in different traffic microenvironments influences individuals’ daily travel satisfaction. Findings show that travel satisfaction and co-exposure to real-time air pollution and noise vary greatly among different transportation modes. People travelling by public transport experience high personal noise exposure and tend to have lower levels of travel satisfaction. While perceived air pollution and noise have significant direct effects on travel experiences, the pathways between objective pollution and travel satisfaction differ for air pollution and noise. Objective air pollution negatively affects travel satisfaction indirectly by influencing perceived air pollution, whereas objective noise has a positive and direct effect on travel satisfaction. Moreover, people with different socio-economic backgrounds tend to bear unequal burdens of air pollution and noise during their daily travels. These findings indicate that more research should be conducted to enhance our understanding of the relationships between personal micro-environmental exposures and subjective wellbeing.

Association of Ultraviolet Radiation Exposure With Dermatomyositis in a National Myositis Patient Registry.

Dermatomyositis (DM) has been associated with geospatial differences in ultraviolet (UV) radiation, but the role of individual determinants of UV exposure prior to diagnosis is unknown. The objective was to examine the role of those individual determinants. We analyzed questionnaire data from 1,350 adults in a US national myositis registry (638 with DM, 422 with polymyositis [PM], and 290 with inclusion body myositis [IBM] diagnosed at ages 18-65 years), examining the likelihood of DM compared with PM and IBM diagnosis, in relation to self-reported sunburn history and job- and hobby-related sun exposures in the year prior to diagnosis. We estimated odds ratios (ORs) and 95% confidence intervals (95% CIs) using logistic regression adjusted for age, skin tone, and sex, to determine the association of individual UV exposures with DM diagnosis. We also evaluated the proportion of DM by maximum daily ambient UV exposure, based on UVB erythemal irradiances for participant residence in the year prior to diagnosis. DM was associated with sunburn in the year before diagnosis (2 or more sunburns OR 1.77 [95% CI 1.28-2.43] versus PM/IBM; 1 sunburn OR 1.44 [95% CI 1.06-1.95]) and with having elevated job- or hobby-related sun exposure (high exposure OR 1.64 [95% CI 1.08-2.49] or moderate exposure OR 1.35 [95% CI 1.02-1.78] versus low or no exposure). Ambient UV intensity was associated with DM in females (β = 3.97, P = 0.046), but not overall. Our findings suggest that high or moderate personal exposure to intense sunlight is associated with developing DM compared with other types of myositis. Prospective research on UV exposure as a modifiable risk factor for DM is warranted.

Risk Exposure and Attention to the Macroeconomy

We conduct an experiment with a representative sample from the US to study households’ demand for macroeconomic information. Respondents who learn of a higher personal exposure to unemployment risk during recessions increase their demand for an expert forecast about the likelihood of a recession. Our findings are consistent with the basic premise of theories of rational inattention that demand for information depends on its expected benefit. Moreover, the fact that perceived risk exposure responds to information highlights frictions in households’ knowledge about the personal relevance of particular pieces of information. Our findings inform the modeling of information frictions in macroeconomics.

Personal Exposure to PM2.5 in the Massive Transport System of Bogotá and Medellín, Colombia

Recent studies have shown that public transport users can be exposed to high levels of pollution emitted from their own vehicles and nearby sources. The purpose of this research is to determine the personal exposure of passengers to PM2.5 inside the vehicles of the massive public transport of two of the main and more populated cities of Colombia, Bogotá and Medellín. TM (TransMilenio powered by diesel) and SITVA (electric and gas natural vehicles) were the systems studied. Were evaluated the integration of new vehicles with technologies Euro V and Euro VI in the TM system, the impact of the weekend effect on personal exposure into public transport (TM and SITVA), and the possible differences between personal exposure regarding the ways of the systems (mixed lane or exclusive lane for TM and SITVA). To measure PM2.5 levels, a DustTrak monitor previously calibrated was used. This measurement campaigns lasted for more than 80 hours and a mean of 17000 data of PM2.5 concentrations were obtained for each route. The personal dose was calculated based on the recorded data. The mean PM2.5 concentrations and personal dose found in the research for TM are 167 µg/m³ and 2.3 µg/min, respectively, while, for SITVA they are 41 µg/m³ and 0.53 µg/min, respectively. Therefore, SITVA users have a 5 times lower personal exposure to PM2.5 than TM users. It was also found that due to the poor proportion of new TM vehicles during the monitoring period, the personal exposure in the old vehicles and in the new ones is similar. In the case of SITVA, it was evidenced that the mixed lane contributes to a high personal exposure to PM2.5 than the exclusive one.

In-car particulate matter exposure across ten global cities

Cars are a commuting lifeline worldwide, despite contributing significantly to air pollution. This is the first global assessment on air pollution exposure in cars across ten cities: Dhaka (Bangladesh); Chennai (India); Guangzhou (China); Medellín (Colombia); São Paulo (Brazil); Cairo (Egypt); Sulaymaniyah (Iraq); Addis Ababa (Ethiopia); Blantyre (Malawi); and Dar-es-Salaam (Tanzania). Portable laser particle counters were used to develop a proxy of car-user exposure profiles and analyse the factors affecting particulate matter ≤2.5 μm (PM2.5; fine fraction) and ≤10 μm (PM2.5–10; coarse fraction). Measurements were carried out during morning, off- and evening-peak hours under windows-open and windows-closed (fan-on and recirculation) conditions on predefined routes. For all cities, PM2.5 and PM10 concentrations were highest during windows-open, followed by fan-on and recirculation. Compared with recirculation, PM2.5 and PM10 were higher by up to 589% (Blantyre) and 1020% (São Paulo), during windows-open and higher by up to 385% (São Paulo) and 390% (São Paulo) during fan-on, respectively. Coarse particles dominated the PM fraction during windows-open while fine particles dominated during fan-on and recirculation, indicating filter effectiveness in removing coarse particles and a need for filters that limit the ingress of fine particles. Spatial variation analysis during windows-open showed that pollution hotspots make up to a third of the total route-length. PM2.5 exposure for windows-open during off-peak hours was 91% and 40% less than morning and evening peak hours, respectively. Across cities, determinants of relatively high personal exposure doses included lower car speeds, temporally longer journeys, and higher in-car concentrations. It was also concluded that car-users in the least affluent cities experienced disproportionately higher in-car PM2.5 exposures. Cities were classified into three groups according to low, intermediate and high levels of PM exposure to car commuters, allowing to draw similarities and highlight best practices.

Air Pollutant Exposure and Stove Use Assessment Methods for the Household Air Pollution Intervention Network (HAPIN) Trial.

Background:High quality personal exposure data is fundamental to understanding the health implications of household energy interventions, interpreting analyses across assigned study arms, and characterizing exposure–response relationships for household air pollution. This paper describes the exposure data collection for the Household Air Pollution Intervention Network (HAPIN), a multicountry randomized controlled trial of liquefied petroleum gas stoves and fuel among 3,200 households in India, Rwanda, Guatemala, and Peru.Objectives:The primary objectives of the exposure assessment are to estimate the exposure contrast achieved following a clean fuel intervention and to provide data for analyses of exposure–response relationships across a range of personal exposures.Methods:Exposure measurements are being conducted over the 3-y time frame of the field study. We are measuring fine particulate matter [PM in aerodynamic diameter ()] with the Enhanced Children’s MicroPEM™ (RTI International), carbon monoxide (CO) with the USB-EL-CO (Lascar Electronics), and black carbon with the OT21 transmissometer (Magee Scientific) in pregnant women, adult women, and children of age, primarily via multiple 24-h personal assessments (three, six, and three measurements, respectively) over the course of the 18-month follow-up period using lightweight monitors. For children we are using an indirect measurement approach, combining data from area monitors and locator devices worn by the child. For a subsample (up to 10%) of the study population, we are doubling the frequency of measurements in order to estimate the accuracy of subject-specific typical exposure estimates. In addition, we are conducting ambient air monitoring to help characterize potential contributions of exposure from background concentration. Stove use monitors (Geocene) are being used to assess compliance with the intervention, given that stove stacking (use of traditional stoves in addition to the intervention gas stove) may occur.Conclusions:The tools and approaches being used for HAPIN to estimate personal exposures build on previous efforts and take advantage of new technologies. In addition to providing key personal exposure data for this study, we hope the application and learnings from our exposure assessment will help inform future efforts to characterize exposure to household air pollution and for other contexts. https://doi.org/10.1289/EHP6422

Contribution of Chinese Hot Pot and Barbecue Restaurants on Indoor Environmental Parameters

ABSTRACT The indoor environmental quality of hot pot and barbecue restaurants has caused an increasing amount of public concern. Hence, this study assessed the conditions and ventilation systems in nine such restaurants of Xi’an, China, by performing field measurements focusing on the variations in temperature, relative humidity, and CO and CO2 concentrations due to cooking style. The results showed that the indoor environmental quality of the test restaurants depended mainly on the cooking fuel, cooking method and ventilation system. Boiling food in soup (hot pot) raised the relative humidity inside the restaurants. However, without sufficient ventilation, cooking with radiation (hot pot/barbecue) resulted in high personal heat exposure and low relative humidity near the heat sources. A substantial rise in the CO level was observed with the burning of charcoal, whereas an increase in the CO2 concentration was detected with the combustion of natural gas. Furthermore, the operational condition of the kitchen ventilation significantly affected the air quality in the dining area, which was found to be the worst at the restaurant exhibiting the poorest ventilation (i.e., the lowest contaminant removal and heat removal efficiencies). Thus, a more efficient and energy-saving ventilation system for hot pot and barbecue restaurants should be developed.

Repurposing Orthopaedic Residents Amid COVID-19: Critical Care Prone Positioning Team.

Repurposing Orthopaedic Residents Amid COVID-19: Critical Care Prone Positioning Team.

Psychological impact of noise exposure among machine and non-machine operators in construction industry

Noise hazard is reported as a serious issue among the construction industry in Malaysia. The aim of the study is to determine the personal noise exposure level and the prevalence of psychological health effect symptoms among the machine and non-machine operators on construction site in Malaysia. Sixty-one (61) construction workers were participated as respondents and categorized into machine and non-machine operators group. All respondents were monitored for 8 hours working time using personal noise dosimeter for personal noise monitoring. Questionnaires and interviewed sessions were used to determine the prevalence of psychological health effect symptoms. The results obtained reveal that the construction workers have high personal noise exposure level where machine operators are significantly higher compared to non-machine operators. The prevalence of psychological health effect symptoms among machine operators is 89% higher than the non-machine operators. Lastly, there is a significant positive relationship between the personal noise exposure level and the prevalence of psychological health effect symptoms among the construction workers.

Risk assessment of personal exposure to polycyclic aromatic hydrocarbons and aldehydes in three commercial cooking workplaces

Cooking-related emissions are associated with environmental pollution and adverse health effects. Of the various chemical species emitted during cooking, polycyclic aromatic hydrocarbons (PAHs) and aldehydes are two chemical species with carcinogenic or tumor promoting characteristics. Although PAH exposure has been studied in commercial kitchen workers, few studies have investigated simultaneous exposure to PAHs and aldehydes in these workers. The aims of this study were to compare personal concentrations of PAH and aldehyde in three commercial cooking workplaces and to estimate their corresponding cancer risks. The three cooking workplaces included western fast food restaurant kitchens, Chinese cafeteria kitchens, and street food carts. Comparisons showed that workers in western fast food restaurant kitchens and Chinese cafeteria kitchens tended to have lower personal concentrations of these pollutants compared to workers in street food carts. The geometric mean (95% CI) cancer risks in the three workplaces were, from lowest to highest, 1.36 (1.12–1.67) × 10−5 for western fast food restaurant kitchens, 1.52 (1.01–2.28) × 10−5 for Chinese cafeteria kitchens, and 3.14 (2.45–4.01) × 10−5 for street food carts. The percentage contributions of aldehyde species to cancer risk were very high (74.9–99.7%). Street food cart workers had high personal exposure to aldehyde probably due to lack of effective exhaust systems. Thus, their cancer risk was significantly higher than those of workers in western fast food restaurant kitchens (p < 0.001) and Chinese cafeteria kitchens (p = 0.013).

Personal exposure of PM2.5 emitted from solid fuels combustion for household heating and cooking in rural Guanzhong Plain, northwestern China

Household solid fuel combustion for heating and cooking in rural areas is an important source of fine particulate matter (PM2.5) in northwestern China, which largely contributes to PM2.5 personal exposure concentrations during the cold winter. There is a general lack of understanding about the personal exposure to PM2.5 and to its chemical components emitted from domestic solid fuel combustion in northwestern Chinese rural populations. In this work, personal exposure to PM2.5 was sampled using a portative device together with fixed indoor and outdoor fixed samplings in Guanzhong Plain in December 2016 for the purpose of characterizing personal exposure to PM2.5 as a function of different solid fuels used in rural households. The average housewife's personal exposure to PM2.5 concentration was 263.4 ± 105.8 μg m−3 (1σ, n = 30), which was about 40% higher than the values found indoors (186.5 ± 79.5 μg m−3, 1σ, n = 30) and outdoors (191.0 ± 85.3 μg m−3, 1σ, n = 30). High personal exposure PM2.5 levels were mainly related to the ignition of solid fuels for heating and cooking. Correlations among personal exposure, indoor and outdoor PM2.5 levels and their mutual ratios were computed to investigate how personal exposure to fine aerosols can be related to microenvironmental PM2.5 levels and to individual activities. The results showed that households using electric power for heating and cooking were characterized by an average personal exposure PM2.5 value of 156.8 ± 36.6 μg m−3 (1σ, n = 6) while personal exposure to PM2.5 in households using solid fuels was twice higher (310.8 ± 90.4 μg m−3, 1σ, n = 24). Solid fuel combustion products and related secondary formed species dominated PM2.5 mass in personal exposure, indoor and outdoor samples. Motor vehicle emission and various dust sources were two other main contributors identified. Our results demonstrated that the use of clean energy could be an effective measure to reduce personal exposure levels of PM2.5 emitted from domestic solid fuels combustion in winter in rural areas, which implied that the government should speed up the upgrade of the heating and cooking equipment fleet to protect the health of rural residents in northwestern China.

Comparison of particulate matter exposure estimates in young children from personal sampling equipment and a robotic sampler

Accurate characterization of particulate matter (PM) exposure in young children is difficult, because personal samplers are often too heavy, bulky or impractical to be used. The Pretoddler Inhalable Particulate Environmental Robotic (PIPER) sampler was developed to help address this problem. In this study, we measured inhalable PM exposures in 2-year-olds via a lightweight personal sampler worn in a small backpack and evaluated the use of a robotic sampler with an identical sampling train for estimating PM exposure in this age group. PM mass concentrations measured by the personal sampler ranged from 100 to almost 1,200 μg/m3, with a median value of 331 μg/m3. PM concentrations measured by PIPER were considerably lower, ranging from 14 to 513 μg/m3 with a median value of 56 μg/m3. Floor cleaning habits and activity patterns of the 2-year-olds varied widely by home; vigorous play and recent floor cleaning were most associated with higher personal exposure. Our findings highlight the need for additional characterization of children's activity patterns and their effect on personal exposures.

Household air pollution and personal exposure to nitrated and oxygenated polycyclic aromatics (PAHs) in rural households: Influence of household cooking energies.

Residential solid fuels are widely consumed in rural China, contributing to severe household air pollution for many products of incomplete combustion, such as polycyclic aromatic hydrocarbons (PAHs) and their polar derivatives. In this study, concentrations of nitrated and oxygenated PAH derivatives (nPAHs and oPAHs) for household and personal air were measured and analyzed for influencing factors like smoking and cooking energy type. Concentrations of nPAHs and oPAHs in kitchens were higher than those in living rooms and in outdoor air. Exposure levels measured by personal samplers were lower than levels in indoor air, but higher than outdoor air levels. With increasing molecular weight, individual compounds tended to be more commonly partitioned to particulate matter (PM); moreover, higher molecular weight nPAHs and oPAHs were preferentially found in finer particles, suggesting a potential for increased health risks. Smoking behavior raised the concentrations of nPAHs and oPAHs in personal air significantly. People who cooked food also had higher personal exposures. Cooking and smoking have a significant interaction effect on personal exposure. Concentrations in kitchens and personal exposure to nPAHs and oPAHs for households using wood and peat were significantly higher than for those using electricity and liquid petroleum gas (LPG).

Occupational exposures to radiofrequency fields: results of an Israeli national survey

Relatively high exposures to radiofrequency (RF) fields can occur in the broadcast, medical, and communications industries, as well in occupations that use RF emitting equipment (e.g. law enforcement). Information on exposure to workers employed in these industries and occupations is limited. We present results of an Israeli National Survey of occupational RF field levels at frequencies between ~100 kHz and 40 GHz, representing Industrial Heating, Communications, Radar, Research, and Medicine. Almost 4300 measurements from 900 sources across 25 occupations were recorded and categorised as ‘routine’, ‘incidental’, or ‘unintended’. The occupation-specific geometric means (GMs) of the percentage of the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs) for each of the three exposure scenarios are presented together with the geometric standard deviation (GSD). Additionally, we present estimates of occupation-specific annual personal exposures and collective exposures. The vast majority of the GM of routine exposures ranged from a fraction to less than 1% of ACGIH TLVs, except for Walkie-Talkie (GM 94% of ACGIH), Induction Heating (17%), Plastic Welding (11%), Industrial Heating (6%) and Diathermy (6%). The GM of incidental and unintended exposures exceeded the TLV for one and 14 occupations, respectively. In many cases, the within-occupation GSD was very large, and though the medians remained below TLV, variable fractions of these occupations were projected to exceed the TLV. In rank order, Walkie-Talkie, Plastic Welding, and Induction Heating workers had the highest annual cumulative personal exposure. For cumulative collective exposures within an occupation, Walkie-Talkie dominated with 96.3% of the total, reflecting both large population and high personal exposure. A brief exceedance of the TLV does not automatically translate to hazard as RF exposure limits (issued by various bodies, including ACGIH) include a 10-fold safety factor relative to thermal thresholds and are based on a 6 min averaging period.

Individual Exposure to Air Pollutants in a Portuguese Urban Industrialized Area

Industrial development from the second half of the 20th century coupled with population growth and concentration in urban areas has accentuated the concern for potential effects and impacts from air pollutant emissions on environmental and human health. This study examined the Estarreja region, an urban area that has one of the largest chemical complexes in Portugal, a complex that was recently under expansion. In the scope of the INSPIRAR project, individual daily exposure of a group of individuals to particulate matter of 10 μm aerodynamic diameter (PM10) and nitrogen dioxide (NO2) in two phases was determined using a microenvironmental approach. In this context, personal daily activity profiles of individuals were established for their normal routine by personal interviews. These profiles enabled determination of where each individual was at each moment of the day. Utilizing this information with hourly air quality maps simulated with URBAIR air quality model and indoor/outdoor relationships, it was possible to calculate personal daily exposure of each individual to air pollutants. Results from the analysis of daily activity profiles showed a high level of sedentariness of this population and long durations spent indoors. The studied individuals displayed high personal PM10 and NO2 exposure variability. Data demonstrated possible error when a single concentration measurement was assumed as a proxy of exposure. In general, no significant differences were found between the two population groups, indicating that workers of the chemical complex were not exposed to a greater extent to PM10 and NO2 than the general population working in the same area.

Exposure and preventive measure to reduce high and daily exposure to Bacillus thuringiensis in potted plant production.

The bacterium Bacillus thuringiensis (Bt) is the active organism in a variety of commercially available products used worldwide as biopesticides. Bt products are applied in large outdoor areas as well as in indoor environments. Even though it has been sold for decades, not much is known about the occupational exposure to Bt. The aim of this study was to obtain knowledge about the exposure to Bt subspecies israelensis (Bti) in a propagation section in a greenhouse, where Bti is applied hourly by a spray boom, and to test a preventive measure to reduce the exposure to airborne Bti. Furthermore, we wanted to study the exposure during work with potted plants treated earlier with Bti. Exposure to aerosols with Bti was measured repeatedly by personal and stationary samplers before and after the intervention. Bti was identified by polymerase chain reaction in air and soil samples. Personal exposure to inhalable Bti in the propagation section was 3×10(5) cfu m(-3) (median level, n = 22); the personal exposure of people working with plants treated earlier with Bti was 3200 cfu m(-3) (median level, n = 17). The highest single measure was found for the person working with the spray boom (7×10(5) cfu m(-3)) but airborne Bti was present at all sampling stations in the propagation section. Bti constituted a high share of the airborne cultivable bacteria and a smaller share of the soilborne bacteria in the propagation section. In a human cell assay, spiking an aerosol sample with a product with Bti increased the inflammatory potential of an aerosol sample from the greenhouse significantly. Based on the inflammatory potential and the high personal exposure, a cover around the spray boom was built as an attempt to reduce the daily exposure to Bti. The cover reduced the personal exposure to Bti from 3.0×10(5) cfu m(-3) to 1.8×10(4) cfu m(-3). The exposure was thus reduced by a factor 17, which is a considerable reduction. Bti was present in different particle size fractions with the majority, both before and after the intervention, in the fraction of airborne particles with an aerodynamic diameter between 1.2 and 3.0 µm. The measured occupational exposure to Bti is discussed in relation to risk evaluation.

PERSONAL EXPOSURE TO ASBESTOS FIBERS AMONG TRANSMISSION MECHANICS IN REPAIR SHOPS IN BOGOTA, COLOMBIA

Background: In Colombia the transmission system of vehicles still use asbestos containing clutch discs. Clutch discs are sold separated from the clutch plates (i.e., support). Thus, it is necessary to manipulate the discs in order to attach them to the plate before installation. These activities may release asbestos fibers, which may expose workers. Aims: Estimate personal exposures to asbestos fibers among transmission mechanics that manipulate asbestos containing clutch discs, in repair shops located in Bogotá, Colombia. Methods: Personal and area samples were collected and analyzed following NIOSH methods 7400 and 7402, in a transmission repair shop. Samples were collected during three consecutive days for the entire working shift (8am-6:00 pm). Personal samples and short-term personal samples (30 min.) were collected in the respiratory zone of three workers (i.e., two riveters and one administrative staff). Results: A total of 75 air samples were collected during the monitoring campaign (i.e., 60 personal samples, 11 area samples, 3 blanks, and 1 background). The 8-hr TWA personal fiber concentrations for riveters ranged between 0,066 to 0,169 f/cc (PCM). The manipulation of clutch discs (i.e., drilling, countersinking, riveting, manual grinding, and in some occasions grinding with a machine) was the activity associated with the highest personal exposures. Other activities associated with high exposures included volatilization of fibers because of working on contaminated surfaces and dry cleaning of the manipulation equipment. Personal samples of administrative staff did not indicate high fiber exposures. Conclusions: Few studies have been conducted to understand the risks of this occupational group, and none of the previous studies cover the manipulation activities observed in the current study. This study suggests that workers manipulating asbestos containing clutch discs maybe exposed to high fiber concentrations.

Local Perceptions of the Forms, Timing and Causes of Behavior Change in Response to the AIDS Epidemic in Zimbabwe

Quantitative studies indicate that HIV incidence in Zimbabwe declined since the late 1990s, due in part to behavior change. This qualitative study, involving focus group discussions with 200 women and men, two dozen key informant interviews, and historical mapping of HIV prevention programs, found that exposure to relatives and close friends dying of AIDS, leading to increased perceived HIV risk, was the principal explanation for behavior change. Growing poverty, which reduced men's ability to afford multiple partners, was also commonly cited as contributing to reductions in casual, commercial and extra-marital sex. HIV prevention programs and services were secondarily mentioned as having contributed but no specific activities were consistently indicated, although some popular culture influences appear pivotal. This qualitative study found that behavior change resulted primarily from increased interpersonal communication about HIV due to high personal exposure to AIDS mortality and a correct understanding of sexual HIV transmission, due to relatively high education levels and probably also to information provided by HIV programs.

Fine particles and carbon monoxide from wood burning in 17th–19th century Danish kitchens: Measurements at two reconstructed farm houses at the Lejre Historical–Archaeological Experimental Center

Carbon monoxide (CO) and particulate matter (PM 2.5) were measured in two reconstructed Danish farmhouses (17–19th century) during two weeks of summer. During the first week intensive measurements were performed while test cooking fires were burned, during the second week the houses were monitored while occupied by guest families. A masonry hearth was located in the middle of each house for open cooking fires and with heating stoves. One house had a chimney leading to the outside over the hearth; in the other, a brickwork hood led the smoke into an attic and through holes in the roof. During the first week the concentration of PM 2.5 averaged daily between 138 and 1650 μg m −3 inside the hearths and 21–160 μg m −3 in adjacent living rooms. CO averaged daily between 0.21 and 1.9 ppm in living areas, and up to 12 ppm in the hearths. Highest concentrations were measured when two fires were lit at the same time, which would cause high personal exposure for someone working in the kitchens. 15 min averages of up to 25 400 μg m −3 (PM 2.5) and 260 ppm CO were recorded. WHO air quality guidelines were occasionally exceeded for CO and constantly for PM 2.5. However, air exchange and air distribution measurements revealed a large draw in the chimney, which ensured a fast removal of wood smoke from the hearth area. The guest families were in average exposed to no more than 0.21 ppm CO during 48 h. Based on a hypothetical time-activity pattern, however, a woman living in this type of house during the 17–19th century would be exposed to daily averages of 1.1 ppm CO and 196 μg m −3 PM 2.5, which exceeds WHO guideline for PM 2.5, and is comparable to what is today observed for women in rural areas of developing countries.