Differences In Exposure Rates Research Articles

Postnatal corticosteroid exposure in very preterm infants: A French cohort study.

Background: Postnatal corticosteroids (PC) are widely used in very preterm infants. International reports and national multicenter trials describe a marked variability across countries and inter-sites, in the use of PC. Few information is available on therapeutic indications and prescription characteristics of PC. Aim: The main objective of this study was to describe the exposure to PC in a large cohort of preterm infants born at less than 32weeks of gestation, according to the prescription data of 41 tertiary-care NICUs in France. Secondary objectives were to describe therapeutic indications, day of life (DOL) of the first exposure, route of administration, duration, cumulative dose for each drug, and differences in exposure rates across centers. Methods: We conducted a prospective observational cohort analysis from January 2017 to December 2021, in 41 French tertiary-care NICUs using the same computerized order-entry system. Results: In total, 13,913 infants [birth weight 1144.8 (±365.6) g] were included. Among them, 3633 (26.1%) were exposed to PC, 21.8% by systemic and 10.1% by inhaled route. Within the study population, 1,992 infants (14.3%) received the first corticosteroid treatment in the first week of life and 1641 (11.8%) after DOL 7. The more frequent indications were prevention and/or treatment of bronchopulmonary dysplasia, and arterial hypotension. Hydrocortisone was the more often prescribed molecule. For systemic PC the first exposure occurred in mean at DOL 9.4 (±13.5), mean duration of treatment was 10.3 (±14.3) days, and the cumulative dose (expressed as the equivalent dose of hydrocortisone) was in median [IQR] 9.0 [5.5-28.8] mg/kg. For inhaled PC, the first exposure occurred in mean at DOL 34.1 (±19.7), and mean duration of treatment 28.5 (±24.4) days. The exposure rate ranged from a minimum of 5% to a maximum of 56% among centers, and significantly increased over the study period (p < 0.0001). Conclusion: In this French cohort of very preterm infants, around one patient out to five was exposed to PC during hospital stay in the NICU. The exposure occurred early, starting from the first week of life. Exposure rate widely varied among centers. Pharmacoepidemiology studies are useful to increase knowledge on corticosteroid utilization patterns in preterm infants.

Preliminary Evidence of Anticoagulant Rodenticide Exposure in American Kestrels (Falco sparverius) in the Western United States

ABSTRACT Although there is extensive evidence of declines in the American Kestrel (Falco sparverius) population across North America, the cause of such declines remains a mystery. One hypothesized driver of decline is anticoagulant rodenticide (AR) exposure, which could potentially cause mortality or reduced fitness. We investigated AR exposure in wild American Kestrels in Utah, USA. We collected and tested for AR residues in liver samples (n = 8) from kestrels opportunistically encountered dead and in blood samples (n = 71) from live wild kestrels, both nestlings and adults. We found high detection rates in both tissues. Adult kestrels were more likely to exhibit exposure than juveniles sampled in nests. Three-quarters (six of eight) of tested liver samples from adult kestrels exhibited evidence of AR exposure. Additionally, liver samples (n = 19) opportunistically collected from seven species of raptors within our study area had detectable levels of AR residues, with seven of eight raptor species evidencing exposure; across all raptors, five ARs were detected in liver samples, with brodifacoum the most prevalent, being found in over half (14 of 27) of samples. Over half (7 of 12) of the blood samples from adult kestrels had detectible levels of ARs, while only one of 59 juvenile nest samples tested positive. The difference in exposure rates between adults and juveniles could indicate differential exposure pathways by age class. Based on these findings, we recommend that ARs be further investigated as a potential cause of kestrel declines. Future research could focus on expanding sampling to provide sufficient sample sizes to test for potential nonlethal effects of AR exposure (e.g., fecundity, nesting success), identifying potential exposure pathways, and developing methods for passive sampling of ARs in excreta.

Posttreatment Exposure Rates for 90Y-Microsphere Patients: A Comparison of Products.

There has been a significant increase in the use of 90Y-microspheres in treating liver malignancies. This increase could be seen over the last 30 y, and Food and Drug Administration approval of 2 products-Sirtex SIR-Spheres and Boston Scientific TheraSphere-has helped in the proliferation of these treatments. As the increase in use of both products rose at our institution, there was a need to determine whether there should be special considerations for patients who receive one product compared with patients who receive the other product. This determination was made by measuring exposure rates for several regions of the patient before and after implantation. An independent-samples t test analysis (ɑ = 0.05) was performed for 50 patients (25 TheraSphere and 25 SIR-Spheres) to determine whether the products behaved similarly to the extent that exposure to others was minimized and that as-low-as-reasonably-achievable principles were kept. The results showed that the products exhibited no significant differences in exposure rates, suggesting that no special considerations are needed for the procedure for one product compared with the other.

A comparative analysis of the endoscopic endonasal and pterional approaches for clipping anterior communicating artery aneurysms on three-dimensional printed models.

A comparative analysis of the endoscopic endonasal and pterional approaches for clipping anterior communicating artery aneurysms on three-dimensional printed models.

Influence of School-Based Smoking Prevention Education on Reducing Gap in Exposure to Anti-Tobacco Media Message among Korean Adolescents.

Korean adolescents at high risk for smoking are less exposed to anti-tobacco media messages. This study examines whether school-based smoking prevention education is related to media exposure and whether it can contribute to reducing the gap in exposure to anti-tobacco media messages between smoking vulnerable and non-vulnerable groups. A nationally representative dataset, the 2018 Korea youth risk behavior web-based survey, comprising 59,410 students from grades 7–12, was analyzed. Logistic regression models were designed to evaluate the association between school-based smoking prevention education and media messages exposure. Within-group differences in exposure levels based on sociodemographic characteristics were compared depending on participation or nonparticipation in school-based smoking prevention education. Experience of smoking prevention education within a year was significantly associated with exposure to anti-tobacco media messages. Among Korean adolescents who participated in smoking prevention education compared to those who did not, the media messages exposure rate was more than 20% higher, and the exposure gap within the subgroups by sociodemographic characteristics was narrower. Participation in school-based smoking prevention education was significantly related to media messages exposure. This relationship can be used to improve the overall media messages exposure rate and to reduce the differences in exposure rate based on sociodemographic traits.

Identification and evaluation of flood-avoidance routes in Tucson, Arizona

Campaigns such as “Turn Around, Don't Drown®” encourage motorists to avoid driving into flooded roadways, but thousands of flood-vehicle incidents occur each year. Motorists may not have a feasible alternate route, or they may not be aware of one. Furthermore, few studies within hazards research consider how vulnerability changes as an individual moves through space. A survey of Tucson, Arizona residents included a mapping activity to determine whether their typical routes intersect flood areas, and whether alternate routes exist that avoid flood areas without adding excessive travel time. Of the 452 routes provided, 185 intersect with areas known to flood during routine rain events, affecting 80% of participants. ANOVA revealed no statistically significant differences in exposure rate among groups based on demographic characteristics. Network analyst was used to generate alternate routes that avoid the flood areas and to calculate how much additional time and mileage would be required. Most of the alternate routes added less than one mile to the trip, which is within participants' stated detour tolerance. These findings highlight the potential utility of a decision-support tool to help motorists choose safer, flood-avoiding routes during storms.

13: Route of hysterectomy and mesh attachment at the time of minimally invasive sacrocolpopexy: A retrospective multicenter cohort comparison

To compare outcomes after minimally invasive sacrocolpopexy based on the route of hysterectomy. The primary outcome was rate of mesh exposure. This was a multicenter, retrospective cohort study. Patients who underwent minimally invasive sacrocolpopexy were stratified into three groups by route of hysterectomy: total vaginal hysterectomy (TVH); total laparoscopic hysterectomy (TLH), and laparoscopic supracervical hysterectomy (LSH). Laparoscopic cases included those with robotic assistance. Demographic data, intraoperative and postoperative outcomes were collected. Patients were excluded from analysis of the primary outcome if they had follow-up of less than 6 months (unless they had an exposure prior to 6 months). Data were analyzed using unadjusted methods, with p < 0.05 denoting statistical significance. A total of 501 patients were collected: 263 TVH, 128 TLH, and 110 LSH. Demographic data is described in Table 1. There was a higher average BMI and percentage of postmenopausal patients in the TVH group and a higher rate of active smoking in the TLH group. Primary and secondary outcomes are outlined in Table 2. There was no significant difference in exposure rates between groups: TVH = 6.5% (14/214); TLH = 0% (0/48) for TLH, and LSH = 3.7% (3/79) (p = 0.14). Within the TVH group, 13 of the 14 exposures occurred when the mesh was attached laparoscopically, with only 1 occurring when the mesh was attached vaginally. TVH demonstrated significantly shorter operating time but higher median EBL. When comparing TVH and TLH, TVH had a higher rate of vaginal cuff separation and infection. Within the TVH group, mean OR time was 256 min with vaginal mesh attachment compared to 227 min for laparoscopic attachment. There were no reported ureteral injuries across the three groups, and bowel and bladder injuries were rare. There was insufficient evidence to suggest that route of hysterectomy or preservation of the cervix significantly impacts mesh exposure rates after minimally invasive sacrocolpopexy. The incidence of mesh exposure after vaginal hysterectomy is lower than previously reported, and vaginal attachment of mesh did not demonstrate an increased rate of exposure. The strengths of this study include multicenter collaboration and a relatively large sample size. Limitations include limited follow-up beyond 6 months, retrospective design, and limited number of total exposures.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

In vitro–in vivo extrapolation of hepatic clearance: using virtual experiments to identify a plausibly influential source of inaccuracies

It is understood that entanglement of different methodological and biological factors is responsible for IVIVE uncertainties, but untangling them using wet‐lab and correlation methods has proven difficult. It seems likely that the relative importance of entangled factors will often be use‐case specific, making the problem even more daunting. We are assessing the scientific utility of using virtual experiments to explore for sources of influential extrapolation inaccuracies arising from simplifying assumptions often made about the hepatic disposition of chemical entities, ceteris paribus. We anticipate that, when a significant source is identified, mitigating methods can be developed. Consequently, the prospect of utilizing IVIVEs to improve applications to model‐based personalized dosing methods may increase.To be scientifically useful, objects of virtual experiments, such as virtual mice, livers (vLivers) and hepatocytes (vHPCs) must meet demanding representational requirements. For example, mechanism components are concrete. The organization of components produce a strong behavioral analogy to the referent biology. Within reasonable constraints, events occurring during execution are biomimetic. Measurements of phenomena are quantitatively similar to referent wet‐lab measurements. Smith et al. (PMID27984590) demonstrate the scientific usefulness of virtual experiments by falsifying the prevailing explanation for the characteristic early pericentral pattern of acetaminophen‐induced hepatic necrosis.A liver model is an essential feature of IVIVE methods. The well‐stirred compartment and parallel tubes models are prevalent. Both models abstract away lobular architecture, although parallel‐tube models often describe sequential metabolism. The working hypothesis during extrapolations is that, by adequately accounting for factors responsible for the drug's intrinsic clearance, lobular architectural influences can be abstracted away. We challenge that hypothesis by experimenting on three types of virtual mice, each having a different vLiver substructure but identical vHPCs (no zonation). The lobular architecture of control vLivers (from Smith et al.) and hepatic lobules are strongly analogous. Two test‐vLivers map to the parallel tube model. They are structural variants of Control vLivers that differ only in opportunities that vCompounds have to enter (or not) a vHPC. During in vitro experiments, the exposure rate of each hepatocyte to the compound under study is the same. That is not the case in vivo or for the three vLivers.We measure each vHPC's exposure rates using two vCompounds. They represent extremes of the virtual intrinsic clearance spectrum. Measured periportal and pericentral differences in exposure rates among the three vLiver types are &gt; 10x. That evidence is sufficient to challenge the above working hypothesis. Using liver models that do not ignore lobular structural influences may provide a strategy to reduce IVIVE inaccuracies while providing a context for future inclusion of individualizable intralobular influences.Support or Funding InformationUCSF Biosystems GroupThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Epidemiology and factors influencing varicella infections in tropical countries including Sri Lanka.

Varicella zoster virus (VZV) infections occur worldwide but the epidemiology differs between different geographical regions. Epidemiology of varicella is partly understood in tropical and subtropical regions. Various hypotheses showing differences in exposure rates in different age groups have been proposed. Exposure to VZV during late childhood or adolescent stage causes high morbidity, especially in high school children, university students and young work force in tropical nations. Exposure to VZV infection or sero-prevalence rates through anti-VZV immunoglobulin G appears to be lower in Sri Lanka, similar to other tropical countries prior to the millennium. In contrast, a more recent study in a group of antenatal women showed a relatively higher exposure rate to VZV when compared to the exposure rates prior to 2004 in Sri Lanka. Climatic factors, socioeconomic conditions, mobility and cultural practices appear to play a role in the differences in the exposure rates to VZV infection in the tropics. In most tropical Asian countries including Sri Lanka, routine vaccination against varicella is not carried out. Individuals with negative history for varicella take the vaccine when there is a necessity. Medical and nursing students take the vaccine prior to their clinical training to avoid adulthood varicella.

Epidemiological characteristics of outpatients exposed to rabies in Weinan City in 2017

Objective To investigate the epidemiological characteristics of outpatients exposed to rabies and to analyze the post-exposure prophylaxis in Weinan City in 2017 in order to provide a scientific basis for the prevention of rabies. Methods Clinical data of all outpatients with exposure to rabies in Wei-nan were collected.Ecxcel 2007 was used for data entry and SPSS13.0 for Chi-square test. Results A total of 32 094 cases were reported with an annual exposure rate of 625.64/100 000 in Weinan in 2017.Animal bites mainly occurred in spring and summer, accounting for 47.47% of the total cases in 2017.There were statistically differences in exposure rate among different age groups (χ2=15.858, P=0.003). Farmers accounted for the largest proportion of the outpatients exposed to rabies (52.34%). Among 31 435 outpatients, 28 181(89.65%) received wound care and rabies vaccination.The vaccination rate of rabies immunoglobulin for patients with grade Ⅲ exposure was 46.93%. Conclusion Comprehensive measures with focuses on compulsory vaccination for domestic dogs and adoption of stray dogs should be implemented to prevent human rabies.Meanwhile, health education rabieson prevention and control should also be strengthened. Key words: Rabies; Exposure; Rabies post-exposure prophylaxis clinic

The Mental Health of British Adults with Intellectual Impairments Living in General Households.

People with intellectual disability or borderline intellectual functioning may have poorer mental health than their peers. The present authors sought to (i) estimate the risk of poorer mental health among British adults with and without intellectual impairments and (ii) estimate the extent to which any between-group differences in mental health may reflect between-group differences in rates of exposure to common social determinants of poorer health. The present authors undertook secondary analysis of confidentialized unit records collected in Wave 3 of Understanding Society. British adults with intellectual impairments living in general households are at significantly increased risk of potential mental health problems than their non-disabled peers (e.g. GHQ Caseness OR=1.77, 95% CI (1.25-2.52), P<0.001). Adjusting for between-group differences in age, gender and indicators of socio-economic position eliminated this increased risk [GHQ Caseness adjusted OR=1.06, 95% CI (0.73-1.52), n.s]. Our analyses are consistent with the hypothesis that the increased risk of poor mental health among people with intellectual impairments may be attributable to their poorer living conditions rather than their intellectual impairments per se. Greater attention should be given to understanding and addressing the impact of exposure to common social determinants of mental health among marginalized or vulnerable groups.

Secondary orbital ball implants after enucleation and evisceration: surgical management, morbidity, and long-term outcome.

To investigate effectiveness of a simplified surgical technique for secondary ball implantation in anophthalmic sockets and to compare long-term results of secondary ball implantation in patients previously enucleated or eviscerated. The study is a case series analysis of the clinical charts of 110 consecutive patients who underwent secondary ball implantation after enucleation or evisceration, from January 1998 to December 2011, under the care of 1 surgeon. Patients undergoing primary evisceration and implant exchange were excluded. Primary surgery was due to trauma in 48.8% patients, endophthalmitis and phthisis bulbi in 25.6%, tumors in 22.1%, and orbital vascular malformations in 3.5%. This study adheres to the principles outlined in the Declaration of Helsinki. Of 110 identified cases, 24 were excluded for insufficient follow-up (less than 2 years); mean follow-up was 6.4 years. Group A patients (previously enucleated) received a polyglactin mesh-wrapped implant. Group B patients (previously eviscerated) kept their own sclera as a secondary anterior capping on the polyglactin mesh-wrapped implant. There were 2 implant exposures (4.9%; 2 of 41) in group A. Hard palate graft was used to repair the exposed implant successfully. No exposure was noted in group B. No statistically significant between-group difference in exposure rate was found. Stable secondary ball implantation can be achieved long term, and a reliable surgical technique is the most important factor in predicting implant stability. In patients who had secondary implants following evisceration, sclera and polyglactin mesh may act as duplicate barriers between anterior surface of implants and overlying tissues.

Predictors of workplace violence among female sex workers in Tijuana, Mexico.

For sex workers, differences in rates of exposure to workplace violence are likely influenced by a variety of risk factors, including where one works and under what circumstances. Economic stressors, such as housing insecurity, may also increase the likelihood of exposure. Bivariate analyses demonstrate statistically significant associations between workplace violence and selected predictor variables, including age, drug use, exchanging sex for goods, soliciting clients outdoors, and experiencing housing insecurity. Multivariate regression analysis shows that after controlling for each of these variables in one model, only soliciting clients outdoors and housing insecurity emerge as statistically significant predictors for workplace violence.

Relative impact of violence exposure and immigrant stressors on Latino youth psychopathology

Latino youth in a low-income urban community are at high risk of exposure to violence. Given an accumulation of factors before, during, and following migration, immigrant youth may be at increased risk of exposure to violence and other relevant stressors (e.g., acculturation stress, language proficiency, acculturation/enculturation, and parental separations). Utilizing a short-term longitudinal design, we assessed exposure to violence and immigrant stressors and examined their relative impact on psychopathology in a sample of 164 Latino youth. Immigrant youth reported greater exposure to immigrant stressors relative to native-born peers, but few differences in rates of exposure to violence emerged. When considered alongside relevant immigration stressors, exposure to violence emerged as the strongest predictor of youth psychopathology. Results suggest that some types of stressors have more consistently deleterious effects on mental health and understanding resilient outcomes may entail considering the meaning attributed to stressors and the resources available to cope with stressors.

Adolescents’ Internalizing Behaviors after Extreme Violence Exposure: A Comparison of Race and Gender for African American and Asian American Youth

This study compares African American and Asian American adolescents in their rates of extreme community violence exposure and consequent internalizing behaviors. Using information from a national longitudinal survey this study found substantial violence exposure rates for both groups. Also, gender differences in exposure rates and adolescent reports of internalizing behaviors after violence exposure were detected. Male African American adolescents had the highest exposure rate, while female Asian American adolescents reported the highest level of internalizing behaviors. These findings suggest further research is needed to better understand the effect of violence exposure on various ethnic minority adolescents. Moreover, social workers and other professionals involved in adolescent services could use these results to improve outreach methods to vulnerable adolescents.

Exposure Rate of Hydroxyapatite Orbital Implants: A 15-Year Experience of 802 Cases

To document the long-term experience with hydroxyapatite (HA) orbital implants (Bio-Eye) and analyze the factors influencing implant exposure, including surgical type, procedural modification, use of different wrapping materials and peg materials. Retrospective observational case series. Eight hundred two eyes from 802 patients who underwent anophthalmic socket surgery (eviscerations, enucleations, secondary implant placements) using HA implants, performed by one surgeon between May 1990 and December 2005. All patients' clinical records were reviewed. Baseline age, cause of anophthalmic surgery, surgical type, size of HA implant, wrapping material, and peg system were recorded. Postoperative complications, especially implant exposure, were recorded separately before and after pegging, and compared according to type of surgery, wrapping material, and peg system. The main cause of anophthalmic surgery was trauma (73%). A variety of wrapping materials have been used, including Tutoplast-dura, Vicryl mesh, autogenous sclera, and polyester-urethane. Implant exposure occurred in 17 patients (2.1%) before pegging and 14 (4.0%) after pegging. The exposure rate was significantly higher in eyes eviscerated without (7.2%) than with (1.1%) keratectomy (P = 0.018), but did not differ according to type of surgery (P = 0.710). When distributed according to 5-year periods, the exposure rate was higher from 1990 to 1994 (4.7%) than in later periods (P = 0.004). In patients who underwent enucleation or secondary implantation, there was no difference in exposure rate between Tutoplast-dura- and Vicryl mesh-wrapped implants (P = 0.235). Among the 353 patients (44.0%) who underwent pegging, those who received titanium-pegged implants had a significantly lower incidence of peg extrusion (5.2%), major discharge (5.2%), and pyogenic granuloma (9.1%) than those with nonsleeved polymethyl methacrylate and sleeved polycarbonate peg materials (P<0.05). Exposures associated with HA orbital implants decreased with the improvement of surgical technique over time and have been managed successfully, both before and after pegging. The incidence of peg-related complications have decreased since the introduction of the titanium peg system.

Porous Implant Exposure: Incidence, Management, and Morbidity

To identify what factors may predispose patients to exposure of porous anophthalmic implants and to determine the outcome of exposed porous implants. Examination of pooled data obtained through a PubMed literature search of English-language publications from 1989 through 2004 using the key words enucleation, evisceration, and socket reconstruction. Porous implants were inserted in 80% (3012 of 3777) of the cases identified from 49 publications. The difference in exposure rate between coralline hydroxyapatite (4.9%) and porous polyethylene (8.1%) implants is primarily related to a higher reported complication rate of uncovered porous polyethylene implants, particularly in retinoblastoma patients. Other techniques associated with increased exposures include wrapping implants with bovine pericardium or polyglactin mesh. Evisceration and secondary procedures did not have statistically different complication rates compared with enucleation. There are more late exposures of porous polyethylene than coralline hydroxyapatite implants. Spontaneous healing of exposures occurred in 13% (19 of 145) of cases. Covering exposures with patch grafts underneath vascularized conjunctival flaps was the most successful method of surgical repair. Implant removal was necessary after 29% (42 of 145) of exposures. Although the published literature between 1989 and 2004 reports higher complication rates for uncovered porous implants and implants wrapped with bovine pericardium or polyglactin mesh, pooling data from different studies may mask very good or poor results obtained by individual surgeons. Spontaneous healing of exposed porous implants is relatively uncommon. However, many exposed porous implants can be salvaged with secondary repair.

Prevention of Exposure of Porous Orbital Implants Following Enucleation

To investigate effectiveness of adding a scleral patch graft on a Vicryl mesh-wrapped porous orbital implant to prevent exposure following enucleation. A retrospective, comparative, nonrandomized study. From October 1996 to February 2006, 74 consecutive patients (74 sockets) who received porous orbital implants primarily or secondarily after enucleation at National Taiwan University Hospital (72 cases) and at Far Eastern Memorial Hospital (2 cases) were collected. Patient demographics, ocular diagnosis, the surgical technique, prior ophthalmic surgery, type, covering, and size of the implant, follow-up periods, and complications associated with pegs and implants were recorded. Group 1 patients received a Vicryl mesh-wrapped implant without a scleral patch graft. Group 2 patients received anterior capping with a scleral patch on the Vicryl mesh-wrapped implant. Of 74 identified cases, 12 were excluded for insufficient follow-up. The 62 remaining cases had more than a two-year follow-up. There were two implant exposures (12%, two of 17) in group 1. Retroauricular myoperiosteal graft and scleral patch were used to repair exposed implants successfully. No exposure was noted in group 2 (n = 45). A significant between-group difference in exposure rate was found (P = .02). Early conjunctival dehiscence followed by spontaneous healing occurred in three group 2 patients. Scleral patch graft and Vicryl mesh can act as duplicate barriers between anterior surface of implants and overlying soft tissue. The modified wrapping technique prevents porous implants from exposure effectively.

Variability of Personal Exposure to Fine Particulates for Urban Commuters Inside Automobiles

Over the past decade, a growing body of evidence has emerged to suggest a causal link between short-duration exposure to elevated levels of fine airborne particulate matter and adverse health consequences. It is believed that much of this peak exposure occurs in transport microenvironments both because of the higher levels of fine particulates associated with road traffic, primarily from diesel exhaust emissions, and because of the significant amount of time people spend traveling (for instance, 80 min/day for residents of Sydney, Australia). Although previous studies have suggested substantial differences in exposure rates because of factors such as choice of mode, route, in-vehicle conditions, and meteorological factors, current measurement techniques have restricted insights to fairly coarse sampling intervals (e.g., every hour and every trip). As a consequence, little tangible evidence is available on how pollution varies over a trip and, most critically, about the location, duration, and magnitude of peak excursions within trips. With these issues in mind, this current paper reports on a study in which capabilities of Global Positioning Systems and real-time particle monitors are combined to address the problem for an urban commute in Sydney. This ability to reference pollution data precisely and spatially, and to identify hot spots in particular, holds considerable promise for both understanding and reporting of such data in the future.

Variability of Personal Exposure to Fine Particulates for Urban Commuters inside Automobiles

Over the past decade, a growing body of evidence has emerged to suggest a causal link between short-duration exposure to elevated levels of fine airborne particulate matter and adverse health consequences. It is believed that much of this peak exposure occurs in transport microenvironments both because of the higher levels of fine particulates associated with road traffic, primarily from diesel exhaust emissions, and because of the significant amount of time people spend traveling (for instance, 80 min/day for residents of Sydney, Australia). Although previous studies have suggested substantial differences in exposure rates because of factors such as choice of mode, route, in-vehicle conditions, and meteorological factors, current measurement techniques have restricted insights to fairly coarse sampling intervals (e.g., every hour and every trip). As a consequence, little tangible evidence is available on how pollution varies over a trip and, most critically, about the location, duration, and magnitude of peak excursions within trips. With these issues in mind, this current paper reports on a study in which capabilities of Global Positioning Systems and real-time particle monitors are combined to address the problem for an urban commute in Sydney. This ability to reference pollution data precisely and spatially, and to identify hot spots in particular, holds considerable promise for both understanding and reporting of such data in the future.