A methodology for estimating exposure-controlled crash risk using traffic Police crash data

Exposure control or case-control methodologies are common techniques for estimating crash risks, however they require either observational data on control cases or exogenous exposure data, such as vehicle-kilometres travelled. This study proposes an alternative methodology for estimating crash risk of road user groups, whilst controlling for exposure under a variety of roadway, traffic and environmental factors by using readily available police-reported crash data. In particular, the proposed method employs a combination of a log-linear model and quasi-induced exposure technique to identify significant interactions among a range of roadway, environmental and traffic conditions to estimate associated crash risks. The proposed methodology is illustrated using a set of police-reported crash data from January 2004 to June 2009 on roadways in Queensland, Australia. Exposure-controlled crash risks of motorcyclists—involved in multi-vehicle crashes at intersections—were estimated under various combinations of variables like posted speed limit, intersection control type, intersection configuration, and lighting condition. Results show that the crash risk of motorcycles at three-legged intersections is high if the posted speed limits along the approaches are greater than 60 km/h. The crash risk at three-legged intersections is also high when they are unsignalized. Dark lighting conditions appear to increase the crash risk of motorcycles at signalized intersections, but the problem of night time conspicuity of motorcyclists at intersections is lessened on approaches with lower speed limits. This study demonstrates that this combined methodology is a promising tool for gaining new insights into the crash risks of road user groups, and is transferrable to other road users.

Maternal exposure to heatwave and preterm birth in Brisbane, Australia

Objective To quantify the short-term effects of maternal exposure to heatwave on preterm birth. Design An ecological study. Setting: A population-based study in Brisbane, Australia. Population All pregnant women who had a spontaneous singleton live birth in Brisbane between November and March in 2000–2010 were studied. Methods Daily data on pregnancy outcomes, meteorological factors, and ambient air pollutants were obtained. The Cox proportional hazards regression model with time-dependent variables was used to examine the short-term impact of heatwave on preterm birth. A series of cut-off temperatures and durations were used to define heatwave. Multivariable analyses were also performed to adjust for socio-economic factors, demographic factors, meteorological factors, and ambient air pollutants. Main outcome measure Spontaneous preterm births. Results The adjusted hazard ratios (HRs) ranged from 1.13 (95% CI 1.03–1.24) to 2.00 (95% CI 1.37–2.91) by using different heatwave definitions, after controlling for demographic, socio-economic, and meteorological factors, and air pollutants. Conclusions Heatwave was significantly associated with preterm birth: the associations were robust to the definitions of heatwave. The threshold temperatures, instead of duration, could be more likely to influence the evaluation of birth-related heatwaves. The findings of this study may have significant public health implications as climate change progresses.

Compliance with standard precautions and occupational exposure reporting among operating room nurses in Australia

Occupational exposures of healthcare workers tend to occur because of inconsistent compliance with standard precautions. Also, incidence of occupational exposure is underreported among operating room personnel. The purpose of this project was to develop national estimates for compliance with standard precautions and occupational exposure reporting practices among operating room nurses in Australia. Data was obtained utilizing a 96-item self-report survey. The Standard Precautions and Occupational Exposure Reporting survey was distributed anonymously to 500 members of the Australian College of Operating Room Nurses. The Health Belief Model was the theoretical framework used to guide the analysis of data. Data was analysed to examine relationships between specific constructs of the Health Belief Model to identify factors that might influence the operating room nurse to undertake particular health behaviours to comply with standard precautions and occupational exposure reporting. Results of the study revealed compliance rates of 55.6% with double gloving, 59.1% with announcing sharps transfers, 71.9% with using a hands-free sharps pass technique, 81.9% with no needle recapping and 92.0% with adequate eye protection. Although 31.6% of respondents indicated receiving an occupational exposure in the past 12 months, only 82.6% of them reported their exposures. The results of this study provide national estimates of compliance with standard precautions and occupational exposure reporting among operating room nurses in Australia. These estimates can now be used as support for the development and implementation of measures to improve practices in order to reduce occupational exposures and, ultimately, disease transmission rates among this high-risk group.

Perceptions that influence occupational exposure reporting

Statistics on health care workers' occupational exposures to bloodborne pathogens underestimate the true extent of the problem because of a tendency for underreporting. A descriptive correlational design was used to investigate compliance with standard precautions and occupational exposure reporting practices among perioperative nurses in Australia. The study found that although intention to report both percutaneous and mucocutaneous exposures was relatively high, mean compliance rates for actually reporting exposures incurred were considerably lower. The perception of barriers to reporting significantly influenced compliance.

The effect of three different (-135°C) whole body cryotherapy exposure durations on elite rugby league players

Background: Whole body cryotherapy (WBC) is the therapeutic application of extreme cold air for a short duration. Minimal evidence is available for determining optimal exposure time. Purpose: To explore whether the length of WBC exposure induces differential changes in inflammatory markers, tissue oxygenation, skin and core temperature, thermal sensation and comfort. Method: This study was a randomised cross over design with participants acting as their own control. Fourteen male professional first team super league rugby players were exposed to 1, 2, and 3 minutes of WBC at -135°C. Testing took place the day after a competitive league fixture, each exposure separated by seven days. Results: No significant changes were found in the inflammatory cytokine interleukin six. Significant reductions (p<0.05) in deoxyhaemoglobin for gastrocnemius and vastus lateralis were found. In vastus lateralis significant reductions (p<0.05) in oxyhaemoglobin and tissue oxygenation index (p<0.05) were demonstrated. Significant reductions (p<0.05) in skin temperature were recorded. No significant changes were recorded in core temperature. Significant reductions (p<0.05) in thermal sensation and comfort were recorded. Conclusion: Three brief exposures to WBC separated by 1 week are not sufficient to induce physiological changes in IL-6 or core temperature. There are however significant changes in tissue oxyhaemoglobin, deoxyhaemoglobin, tissue oxygenation index, skin temperature and thermal sensation. We conclude that a 2 minute WBC exposure was the optimum exposure length at temperatures of -135°C and could be applied as the basis for future studies.

Knowledge, attitudes and practices to reduce exposure among residents living near Danang dioxin hot spot : 2.5 years after a preventative intervention

Da Nang Airbase in Viet Nam served as a bulk storage and supply facility for Agent Orange and other herbicides during Operation Ranch Hand 1961-1971[1]. Studies have shown that environmental and biological samples taken around the airbase site have elevated levels of dioxin [1-3]. Residents living in the vicinity of the airbase are at risk of exposure to dioxin in soil, water and mud and particularly through the consumption of local contaminated food. In 2009, a pre-intervention cross sectional survey was undertaken. This survey examined the knowledge, attitudes and practices (KAP) of householders living near Da Nang Airbase, relevent to reducing dioxin exposure through contaminated food. The results showed that despite living near a severe dioxin hot spot, the residents had very limited knowledge of both exposure risk and measures to reduce exposure to dioxin[4]. In response, the Vietnam Public Health Association (VPHA) and Da Nang Public Health Association implemented a risk reduction program at four residential wards in the vicinities of the Da Nang Airbase in 2010. A post intervention KAP survey was under taken in 2011, and the results showed that knowledge of the existence of dioxin in food, dioxin exposure pathways, potential high risk foods, and preventive measures was significantly enhanced. This new study monitored KAP 2.5 years after the intervention through a 2013 survey of food handlers from 400 households that were randomly selected from the four intervention wards. The results show that most of the positive outcomes remained stable or had increased; some KAP indicators decreased compared to those in the post-intervention survey, but were still significantly higher than the pre-intervention levels. In 2014, these findings will be incorporated with qualitative assessments and the results of laboratory analysis of dioxin concentrations in foods in Da Nang and Bien Hoa dioxin hot spots to comprehensively assess the sustained effects of the intervention.

Exposure to solar ultraviolet radiation is associated with a decreased folate status in women of childbearing age

In vitro studies indicate that folate in collected human blood is vulnerable to degradation after exposure to ultraviolet (UV) radiation. This has raised concerns about folate depletion in individuals with high sun exposure. Here, we investigate the association between personal solar UV radiation exposure and serum folate concentration, using a three-week prospective study that was undertaken in females aged 18–47 years in Brisbane, Australia (153 E, 27 S). Following two weeks of supplementation with 500 μg of folic acid daily, the change in serum folate status was assessed over a 7-day period of measured personal sun exposure. Compared to participants with personal UV exposures of <200 Joules per day, participants with personal UV exposures of 200–599 and >600 Joules per day had significantly higher depletion of serum folate (p = 0.015). Multivariable analysis revealed personal UV exposure as the strongest predictor accounting for 20% of the overall change in serum folate (Standardised B = −0.49; t = −3.75; p = <0.01). These data show that increasing solar UV radiation exposures reduces the effectiveness of folic acid supplementation. The consequences of this association may be most pronounced for vulnerable individuals, such as women who are pregnant or of childbearing age with high sun exposures.

Light exposure and physical activity in myopic and emmetropic children

Purpose: To objectively assess daily light exposure and physical activity levels in myopic and emmetropic children. Methods: One hundred and two children (41 myopes and 61 emmetropes) aged 10 to 15 years old had simultaneous objective measures of ambient light exposure and physical activity collected over a 2 week period during school term, using a wrist worn actigraphy device (Actiwatch-2). Measures of visible light illuminance and physical activity were captured every 30 seconds, 24 hours a day over this period. Mean hourly light exposure and physical activity for weekdays and weekends were examined. To ensure that seasonal variations didn’t confound comparisons, the light and activity data of the 41 myopes, was compared with 41 age and gender matched emmetropes who wore the Actiwatch over the same two week period. Results: Mean light exposure and physical activity for all 101 children with valid data exhibited significant changes with time of day and day of the week (p<0.0001). On average greater daily light exposure occurred on weekends compared to weekdays (p<0.05), and greater physical activity occurred on weekdays compared to weekends (p<0.01). Myopic children (n = 41, mean daily light exposure 915 ± 519 lux) exhibited significantly lower average light exposure compared to 41 age and gender matched emmetropic children (1272 ± 625 lux, p<0.01). The amount of daily time spent in bright light conditions (>1000 lux) was also significantly greater in emmetropes (127 ± 51 minutes) compared to myopes (91 ± 44 minutes, p<0.001). No significant differences were found between the average daily physical activity levels of myopes and emmetropes (p>0.05). Conclusions: Myopic children exhibit significantly lower daily light exposure, but no significant difference in physical activity compared to emmetropic children. This suggests the important factor involved in documented associations between myopia and outdoor activity is likely exposure to bright outdoor light rather than greater physical activity.

Measuring exposure to solar ultraviolet radiation using a dosimetric technique : understanding participant compliance issues

Personal ultraviolet dosimeters have been used in epidemiological studies to understand the risks and benefits of individuals' exposure to solar ultraviolet radiation (UVR). We investigated the types and determinants of non-compliance associated with a protocol for use of polysulphone UVR dosimeters. In the AusD Study, 1,002 Australian adults (aged 18-75 years) were asked to wear a new dosimeter on their wrist each day for 10 consecutive days to quantify their daily exposure to solar UVR. Of the 10,020 dosimeters distributed, 296 (3%) were not returned or used (Type I non-compliance) and other usage errors were reported for 763 (8%) returned dosimeters (Type II non-compliance). Type I errors were more common in participants with predominantly outdoor occupations. Type II errors were reported more frequently on the first day of measurement; weekend days or rainy days; and among females; younger people; more educated participants or those with outdoor occupations. Half (50%) the participants reported a non-compliance error on at least one day during the 10-day period. However, 92% of participants had at least 7 days of usable data without any apparent non-compliance issues. The factors identified should be considered when designing future UVR dosimetry studies.

The contributions of solar ultraviolet radiation exposure and other determinants to Serum 25-Hydroxyvitamin D concentrations in Australian adults : the AusD study

The Quantitative Assessment of Solar UV [ultraviolet] Exposure for Vitamin D Synthesis in Australian Adults (AusD) Study aimed to better define the relationship between sun exposure and serum 25-hydroxyvitamin D (25(OH)D) concentration. Cross-sectional data were collected between May 2009 and December 2010 from 1,002 participants aged 18-75 years in 4 Australian sites spanning 24° of latitude. Participants completed the following: 1) questionnaires on sun exposure, dietary vitamin D intake, and vitamin D supplementation; 2) 10 days of personal ultraviolet radiation dosimetry; 3) a sun exposure and physical activity diary; and 4) clinical measurements and blood collection for 25(OH)D determination. Our multiple regression model described 40% of the variance in 25(OH)D concentration; modifiable behavioral factors contributed 52% of the explained variance, and environmental and demographic or constitutional variables contributed 38% and 10%, respectively. The amount of skin exposed was the single strongest contributor to the explained variance (27%), followed by location (20%), season (17%), personal ultraviolet radiation exposure (8%), vitamin D supplementation (7%), body mass index (weight (kg)/height (m)2) (4%), and physical activity (4%). Modifiable behavioral factors strongly influence serum 25(OH)D concentrations in Australian adults. In addition, latitude was a strong determinant of the relative contribution of different behavioral factors.

What knowledge do ICU nurses have with regard to the effects of noise exposure in the Intensive Care Unit?

This small-scale study was undertaken to assess what knowledge nursing staff from a General Intensive Care Unit held with regard to noise exposure. To assess knowledge a self-administered multiple-choice questionnaire was used. Rigorous peer-review insured content validity. This study produced poor results in terms of the knowledge nurses held with regard to noise related issues in particular the psychophysiological effects and current legislation concerning its safe exposure. Non-parametric testing, using Kruskal–Wallis found no significant difference between nursing grades, however, descriptive analysis demonstrated that the staff nurse grade (D and E) performed better overall. Whilst the results of this study may seem self-evident in some respects, it is the problems of exposure to excessive noise levels for both patients and hospital personnel, which are clearly not understood. The effects noise exposure has on individuals for example decreased wound healing; sleep deprivation and cardiovascular stimulation must be of concern especially in terms of patient care but more so for nursing staff especially the effects noise levels can have on cognitive task performance.

Assessing exposure to polybrominated diphenyl ethers (PBDEs) for workers in the vicinity of a large recycling facility

Increased levels of polybrominated diphenyl ethers (PBDEs) can occur particularly in dust and soil surrounding facilities that recycle products containing PBDEs. This may be the source of increased exposure for nearby workers and residents. To investigate, we measured PBDE levels in soil, office dust and blood of workers at the closest workplace (i.e. within 100m) to a large automotive shredding and metal recycling facility in Brisbane, Australia. The workplace investigated in this study was independent of the automotive shredding facility and was one of approximately 50 businesses of varying types within a relatively large commercial/industrial area surrounding the recycling facility. Concentrations of PBDEs in soils were at least an order of magnitude greater than background levels in the area. Congener profiles were dominated by larger molecular weight congeners; in particular BDE-209. This reflected the profile in outdoor air samples previously collected at this site. Biomonitoring data from blood serum indicated no differential exposure for workers near the recycling facility compared to a reference group of office workers, also in Brisbane. Unlike air, indoor dust and soil sample profiles, serum samples from both worker groups were dominated by congeners BDE-47, BDE-153, BDE-99, BDE-100 and BDE-183 and was similar to the profile previously reported in the general Australian population. Estimated exposures for workers near the industrial point source suggested indoor workers had significantly higher exposure than outdoor workers due to their exposure to indoor dust rather than soil. However, no relationship was observed between blood PBDE levels and different roles and activity patterns of workers on-site. These comparisons of PBDE levels in serum provide additional insight into the inter-individual variability within Australia. Results also indicate congener patterns in the workplace environment did not match blood profiles of workers. This was attributed to the relatively high background exposures for the general Australian population via dietary intake and the home environment.

The effectiveness of an intervention in reducing risk of dioxin exposure in Da Nang : changes in community knowledge, attitudes and prevention practices after 2.5 years

Introduction Environmental and biological samples taken around Da Nang Air Base have shown elevated levels of dioxin over many years [1-3]. A pre-intervention knowledge, attitudes and practices (KAP) survey (2009), a risk reduction program (2010) and a post intervention KAP survey (2011) were undertaken in four wards surrounding Danang Airbase. A follow-up evaluation was undertaken in 2013. Methods A KAP survey was implemented among 400 randomly selected food handlers. Eleven indepth interviews and four focus group discussions were also undertaken. Results The knowledge of respondents remained positive and/or improved at 2.5 years follow-up. There were no significant differences in attitudes toward preventing dioxin exposure across surveys; most respondents were positive in all three surveys. An increase in households (69.5%) undertaking measures to prevent exposure was observed, which was higher than in the pre-intervention survey (39.6%) and post- intervention survey (60.4%) (χ2 = 95.6; p < 0.001). The proportion of respondents practicing appropriate preventive measures was also significantly improved. Conclusions Despite most of the intervention program’s activities ceasing in 2010, the risk reduction program has resulted in positive outcomes over the longer-term, with many knowledge and attitude measures remaining stable or imporving. Some KAP indicators decreased, but these KAP indicators were still significantly higher than the pre-intervention levels.

Human exposure to brominated flame retardants

Human polybrominated diphenyl ether (PBDE) exposure occurs through a range of pathways including: ingestion of dust including hand-to-mouth contact; inhalation (air/particulate matter); and ingestion via food including the unique nutrition sources of human milk and placental transfer. While inhalation has been deemed a minor source of exposure, ingestion of food and dust make greater contributions to overall PBDE body burden with intake via dust reported to be much higher in infants than in adults. PBDEs have been detected in samples of human milk, blood serum, cord blood, and adipose tissue worldwide. Concentrations have been found to be highest in populations from North America, followed by Australia, Europe, and Asia. While factors such as gender and parity may not affect concentrations, occupational exposure and age (infants and children) are associated with higher PBDE concentrations. In contrast to “traditional” persistent organic pollutants, there is an inverse relationship between PBDE body burden and age. Predicted body burden calculated using available information on intake and elimination rates of BFRs appears to underestimate measured human body burden data obtained through analysis of BFRs in blood or human milk. This may be due to unknown exposure or inaccurate elimination data. Further exposure studies should focus on younger age groups and an investigation of human PBDE half-lives.

Stability of the bituminous coal microstructure upon exposure to high pressures of helium

Small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS) measurements of the structure of two Australian bituminous coals (particle size of 1-0.5 mm) before, during, and after exposure to 155 bar of helium were made to identify any effects of pressure alone on the pore size distribution of coal and any irreversible effects upon exposure to high pressures of helium in the pore size range from 3 nm to 10 μm. No irreversible effects upon exposure were identified for any pore size. No effects of pressure on pore size distribution were observed, except for a small effect at a pore size of about 2 μm for one coal. This study provides a convenient baseline for SANS and USANS investigations on sorption of gases at elevated pressures on coals, by distinguishing between the effect of pressure alone on coal pore size distribution and against the effect of the gas to be investigated.