Export 40 results:
Sort by: Author Title Type [ Year  (Desc)]
Kalkstein, AJ, Kalkstein LS, Vanos JK, Eisenman DP, Dixon PG.  2018.  Heat/mortality sensitivities in Los Angeles during winter: a unique phenomenon in the United States. Environmental Health. 17   10.1186/s12940-018-0389-7   AbstractWebsite

Background: Extreme heat is often associated with elevated levels of human mortality, particularly across the mid-latitudes. Los Angeles, CA exhibits a unique, highly variable winter climate, with brief periods of intense heat caused by downsloping winds commonly known as Santa Ana winds. The goal is to determine if Los Angeles County is susceptible to heat-related mortality during the winter season. This is the first study to specifically evaluate heatrelated mortality during the winter for a U.S. city. Methods: Utilizing the Spatial Synoptic Classification system in Los Angeles County from 1979 through 2010, we first relate daily human mortality to synoptic air mass type during the winter season (December, January, February) using Welch's t-tests. However, this methodology is only somewhat effective at controlling for important inter-and intra-annual trends in human mortality unrelated to heat such as influenza outbreaks. As a result, we use distributed lag nonlinear modeling (DLNM) to evaluate if the relative risk of human mortality increases during higher temperatures in Los Angeles, as the DLNM is more effective at controlling for variability at multiple temporal scales within the human mortality dataset. Results: Significantly higher human mortality is uncovered in winter when dry tropical air is present in Los Angeles, particularly among those 65 years and older (p < 0.001). The DLNM reveals the relative risk of human mortality increases when above average temperatures are present. Results are especially pronounced for maximum and mean temperatures, along with total mortality and those 65 +. Conclusions: The discovery of heat-related mortality in winter is a unique finding in the United States, and we recommend stakeholders consider warning and intervention techniques to mitigate the role of winter heat on human health in the County.

Hosokawa, Y, Grundstein AJ, Vanos JK, Cooper ER.  2018.  Environmental Condition and Monitoring. Sport and Physical Activity in the Heat. :147-162.: Springer Abstract
Vanos, JK, Herdt AJ, Lochbaum MR.  2017.  Effects of physical activity and shade on the heat balance and thermal perceptions of children in a playground microclimate. Building and Environment. 126:119-131.   10.1016/j.buildenv.2017.09.026   AbstractWebsite

Outdoor thermal comfort (TC) is an important parameter in assessing the value and health utility of a recreational space. Given the public health significance of child heat illness, the ability to model children's heat balance and TC during activity has received little attention. The current pilot study tests the performance of an outdoor human heat balance model on children playing in warm/hot outdoor environments in sun and shade. Fourteen children aged 9-13 participated in the 8-day study in Texas in spring 2016, performing physical activity while wearing heartrate monitors and completing thermal perception surveys (e.g., actual thermal sensation (ATS)). Surveys were compared to predicted thermal sensation (PTS) based on principles of human-environment heat exchange using personal data and a suite of on-site microclimate information. Results demonstrate the model to significantly predict ATS votes (Spearman's rho = 0.504). Subjective preferred change was also significantly correlated to modeled PTS (rho = -0.607). Radiation, air temperature, windspeed, and level of tiredness were significant predictors of ATS. Finally, the mean human energy balance was significantly lower in the shade (-168 W m(-2)), thus lowering heat stress potential, with the model predicting ATS with little-to-no error (0.2 and 0.0 scale error units in sun and shade, respectively). This study demonstrates an ability to estimate a child's heat balance while accounting for changes in major heat contributors (e.g., radiation, metabolism), and is the first study to evaluate TC of children during activity in outdoor built environments. New insights of heat perception may aid in recognition of often under-recognized heat stress. (C) 2017 Elsevier Ltd. All rights reserved.

Mehdipoor, H, Vanos JK, Zurita-Milla R, Cao GF.  2017.  Short communication: emerging technologies for biometeorology. International Journal of Biometeorology. 61:S81-S88.   10.1007/s00484-017-1399-9   AbstractWebsite

The first decade of the twenty-first century saw remarkable technological advancements for use in biometeorology. These emerging technologies have allowed for the collection of new data and have further emphasized the need for specific and/or changing systems for efficient data management, data processing, and advanced representations of new data through digital information management systems. This short communication provides an overview of new hardware and software technologies that support biometeorologists in representing and understanding the influence of atmospheric processes on living organisms.

Grundstein, A, Knox JA, Vanos J, Cooper ER, Casa DJ.  2017.  American football and fatal exertional heat stroke: a case study of Korey Stringer. International Journal of Biometeorology. 61:1471-1480.   10.1007/s00484-017-1324-2   AbstractWebsite

On August 1, 2001, Korey Stringer, a Pro Bowl offensive tackle for the Minnesota Vikings, became the first and to date the only professional American football player to die from exertional heat stroke (EHS). The death helped raise awareness of the dangers of exertional heat illnesses in athletes and prompted the development of heat safety policies at the professional, collegiate, and interscholastic levels. Despite the public awareness of this death, no published study has examined in detail the circumstances surrounding Stringer's fatal EHS. Using the well-documented details of the case, our study shows that Stringer's fatal EHS was the result of a combination of physiological limitations, organizational and treatment failings, and extreme environmental conditions. The COMfort FormulA (COMFA) energy budget model was used to assess the relative importance of several extrinsic factors on Stringer's EHS, including weather conditions, clothing insulation, and activity levels. We found that Stringer's high-intensity training in relation to the oppressive environmental conditions was the most prominent factor in producing dangerous, uncompensable heat stress conditions and that the full football uniform played a smaller role in influencing Stringer's energy budget. The extreme energy budget levels that led to the fatal EHS would have been avoided according to our modeling through a combination of reduced intensity and lower clothing insulation. Finally, a long delay in providing medical treatment made the EHS fatal. These results highlight the importance of modern heat safety guidelines that provide controls on extrinsic factors, such as the adjustment of duration and intensity of training along with protective equipment modifications based on environmental conditions and the presence of an emergency action plan focused on rapid recognition and immediate on-site aggressive cooling of EHS cases.

Kuras, ER, Richardson MB, Calkins MM, Ebi KL, Hess JJ, Kintziger KW, Jagger MA, Middel A, Scott AA, Spector JT, Uejio CK, Vanos JK, Zaitchik BF, Gohlke JM, Hondula DM.  2017.  Opportunities and Challenges for Personal Heat Exposure Research. Environ Health Perspect. 125:085001.   10.1289/ehp556   Abstract

BACKGROUND: Environmental heat exposure is a public health concern. The impacts of environmental heat on mortality and morbidity at the population scale are well documented, but little is known about specific exposures that individuals experience. OBJECTIVES: The first objective of this work was to catalyze discussion of the role of personal heat exposure information in research and risk assessment. The second objective was to provide guidance regarding the operationalization of personal heat exposure research methods. DISCUSSION: We define personal heat exposure as realized contact between a person and an indoor or outdoor environment that poses a risk of increases in body core temperature and/or perceived discomfort. Personal heat exposure can be measured directly with wearable monitors or estimated indirectly through the combination of time-activity and meteorological data sets. Complementary information to understand individual-scale drivers of behavior, susceptibility, and health and comfort outcomes can be collected from additional monitors, surveys, interviews, ethnographic approaches, and additional social and health data sets. Personal exposure research can help reveal the extent of exposure misclassification that occurs when individual exposure to heat is estimated using ambient temperature measured at fixed sites and can provide insights for epidemiological risk assessment concerning extreme heat. CONCLUSIONS: Personal heat exposure research provides more valid and precise insights into how often people encounter heat conditions and when, where, to whom, and why these encounters occur. Published literature on personal heat exposure is limited to date, but existing studies point to opportunities to inform public health practice regarding extreme heat, particularly where fine-scale precision is needed to reduce health consequences of heat exposure.

Graham, DA, Vanos JK, Kenny NA, Brown RD.  2017.  Modeling the Effects of Urban Design on Emergency Medical Response Calls during Extreme Heat Events in Toronto, Canada. International Journal of Environmental Research and Public Health. 14   10.3390/ijerph14070778   AbstractWebsite

Urban residents are at risk of health-related illness during extreme heat events but the dangers are not equal in all parts of a city. Previous studies have found a relationship between physical characteristics of neighborhoods and the number of emergency medical response (EMR) calls. We used a human energy budget model to test the effects of landscape modifications that are designed to cool the environment on the expected number of EMR calls in two neighborhoods in Toronto, Canada during extreme heat events. The cooling design strategies reduced the energy overload on people by approximately 20-30 W m(-2), resulting in an estimated 40-50% reduction in heat-related ambulance calls. These findings advance current understanding of the relationship between the urban landscape and human health and suggest straightforward design strategies to positively influence urban heat-health.

Vanos, JK, McKercher GR, Naughton K, Lochbaum M.  2017.  Schoolyard shade and sun exposure: Assessment of personal monitoring during children's physical activity. Photochemistry and Photobiology. 93:1123-1132.   10.1111/php.12721   AbstractWebsite

Childhood exposure to ultraviolet radiation ( UVR) is a major risk factor for the development of melanoma later in life. However, it is challenging to accurately determine personal outdoor exposure to UVR, specifically erythemally weighted UVR (UVEry), due to technological constraints, variable time- activity patterns, and the influence of outdoor environmental design. To address this challenge, this study utilized mobile and stationary techniques to examine the UVEry exposures of 14 children in a schoolyard in Lubbock, TX, in spring 2016. The aims of the study were to examine the influence of artificial shade on personal UVEry exposures and to assess full sun exposure ratios (ERs) within the same playground microenvironment. On average, personal wrist dosimeters worn during play in the sun measured 18% of the total onsite UVEry measured by a stationary UV pyranometer. Shade was found to significantly reduce the personal UVEry exposures by 55%, UVB280-315 nm exposures by 91%, and the overall solar radiation by 84%. Substantial benefits can be garnered through focused design of children's recreational space to utilize shade- both natural and artificial-to reduce UVR exposures during play, and to extend safe outdoor stays. Finally, although the wrist is a practical location for a dosimeter, it often underestimates full exposures, particularly during physical activity.

McKercher, GR, Salmond JA, Vanos JK.  2017.  Characteristics and applications of small, portable gaseous air pollution monitors. Environmental Pollution. 223:102-110.   10.1016/j.envpol.2016.12.045   AbstractWebsite

Background: Traditional approaches for measuring air quality based on fixed measurements are inadequate for personal exposure monitoring. To combat this issue, the use of small, portable gas-sensing air pollution monitoring technologies is increasing, with researchers and individuals employing portable and mobile methods to obtain more spatially and temporally representative air pollution data. However, many commercially available options are built for various applications and based on different technologies, assumptions, and limitations. A review of the monitor characteristics of small, gaseous monitors is missing from current scientific literature. Purpose: A state-of-the-art review of small, portable monitors that measure ambient gaseous outdoor pollutants was developed to address broad trends during the last 5-10 years, and to help future experimenters interested in studying gaseous air pollutants choose monitors appropriate for their application and sampling needs. Methods: Trends in small, portable gaseous air pollution monitor uses and technologies were first identified and discussed in a review of literature. Next, searches of online databases were performed for articles containing specific information related to performance, characteristics, and use of such monitors that measure one or more of three criteria gaseous air pollutants: ozone, nitrogen dioxide, and carbon monoxide. All data were summarized into reference tables for comparison between applications, physical features, sensing capabilities, and costs of the devices. Results: Recent portable monitoring trends are strongly related to associated applications and audiences. Fundamental research requires monitors with the best individual performance, and thus the highest cost technology. Monitor networking favors real-time capabilities and moderate cost for greater reproduction. Citizen science and crowdsourcing applications allow for lower-cost components; however important strengths and limitations for each application must be addressed or acknowledged for the given use. (C) 2016 Elsevier Ltd. All rights reserved.

Liu, Y, Zhao N, Vanos JK, Cao G.  2017.  Effects of synoptic weather on ground-level PM2.5 concentrations in the United States. Atmospheric Environment. 148:297-305.   10.1016/j.atmosenv.2016.10.052   Abstract

It is known that individual meteorological factors affect the concentrations of fine particulate matter with aerodynamic diameters ≤2.5 μm (PM2.5), yet the specific meteorological effects found in previous studies are largely inconsistent and even conflicting. This study investigates influences of daily and short term changes in synoptic weather on ground-level PM2.5 concentrations in a large geographical area (75 cities across the contiguous United States (U.S.)) by using ten-year (2001–2010) spatial synoptic classification (SSC) data. We find that in the spring, summer, and fall the presence of the tropical weather types (i.e., dry-tropical (DT) and moist-tropical (MT)) is likely to associate with significantly higher levels of PM2.5 as compared to an all-weather-type-day average, and the presence of the polar weather types (i.e., dry-polar (DP) and moist-polar (MP)) is associated with significantly lower PM2.5 concentrations. The short-term (day to day) changes in synoptic weather types in a region are also likely to lead to significant variance in PM2.5 concentrations. For example, the largest increase in PM2.5 concentration occurs with the synoptic weather type changing from DP-to-MT. Conversely, a MT-to-DP weather type change results in the largest decrease in PM2.5 concentrations. Compared to air temperature, the effects of atmospheric moisture on PM2.5 concentration tend to be subtle, demonstrating that in conjunction with moderate temperature, neither the dry nor the moist air (except moist-moderate (MM) in summer) are associated with significantly high or low PM2.5 concentrations. Finally, we find that the effects of the synoptic weather type on PM2.5 concentrations may vary for different seasons and geographical areas. These findings suggest that interactions between atmospheric factors and seasonal and/or geographical factors have considerable impacts on the PM2.5 concentrations, and therefore should be considered in addition to the SSC when conducting environment health assessments.

Mehdipoor, H, Vanos JK, Zurita-Milla R, Cao G.  2017.  emerging technologies for biometeorology. 61(1):81-88.: Springer Abstract
Joe, P, Belair S, Bernier NB, Bouchet V, Brook JR, Brunet D, Burrows W, Charland JP, Dehghan A, Driedger N.  2017.  The Environment Canada Pan and ParaPan American Science Showcase Project. (2017) Abstract
McGregor, GR, Vanos JK.  2017.  Heat: a primer for public health researchers. : Elsevier Abstract
Allen, MJ, Vanos J, Hondula DM, Vecellio DJ, Knight D, Mehdipoor H, Lucas R, Fuhrmann C, Lokys H, Lees A.  2017.  Supporting sustainability initiatives through biometeorology education and training. 61(1):93-106.: Springer Abstract
Solís, P, Vanos JK, Forbis RE.  2017.  The Decision-Making/Accountability Spatial Incongruence Problem for Research Linking Environmental Science and Policy. Geographical Review. 107:680-704.   10.1111/gere.12240   Abstract

Increasingly, scholars engage policy makers around fundamental, complex questions on environmental change in interdisciplinary settings. Researchers attempting to develop robust contributions to knowledge that can support policymaker understandings in this context face significant inferential challenges in dealing with the spatial dimension of their phenomenon of interest. In this paper, we extend an understanding of well-defined methodological challenges familiar to applied spatial scientists by explicitly articulating the Decision-Making/Accountability, Spatial Incongruence Problem, or DASIP. Three case studies illustrate how spatial incongruences matter to researchers who work on complex, interdisciplinary problems, while seeking to understand decision-making or policy-related phenomenon: urban heat-island mitigation research in Arizona, water transfer conflicts in Kansas, and hydraulic-fracturing debates in Texas. With such examples, we aim to evoke a deeper understanding of this problem in applied research and also inspire thinking about how scholars might innovate methods for creating knowledge about environmental change that supports spatially accountable decision making.

Graham, DA, Vanos JK, Kenny NA, Brown RD.  2016.  The relationship between neighbourhood tree canopy cover and heat-related ambulance calls during extreme heat events in Toronto, Canada. Urban Forestry & Urban Greening. 20:180-186. AbstractWebsite
Cakmak, S, Hebbern C, Cakmak JD, Vanos J.  2016.  The modifying effect of socioeconomic status on the relationship between traffic, air pollution and respiratory health in elementary schoolchildren. Journal of Environmental Management. 177:1-8.   10.1016/j.jenvman.2016.03.051   Abstract

The volume and type of traffic and exposure to air pollution have been found to be associated with respiratory health, but few studies have considered the interaction with socioeconomic status at the household level. We investigated the relationships of respiratory health related to traffic type, traffic volume, and air pollution, stratifying by socioeconomic status, based on household income and education, in 3591 schoolchildren in Windsor, Canada. Interquartile range changes in traffic exposure and pollutant levels were linked to respiratory symptoms and objective measures of lung function using generalised linear models for three levels of income and education. In 95% of the relationships among all cases, the odds ratios for reported respiratory symptoms (a decrease in measured lung function), based on an interquartile range change in traffic exposure or pollutant, were greater in the lower income/education groups than the higher, although the odds ratios were in most cases not significant. However, in up to 62% of the cases, the differences between high and low socioeconomic groups were statistically significant, thus indicating socioeconomic status (SES) as a significant effect modifier. Our findings indicate that children from lower socioeconomic households have a higher risk of specific respiratory health problems (chest congestion, wheezing) due to traffic volume and air pollution exposure.

Dixon, GP, Allen M, Gosling SN, Hondula DM, Ingole V, Lucas R, Vanos J.  2016.  Perspectives on the Synoptic Climate Classification and its Role in Interdisciplinary Research. 10:164.   10.1111/gec3.12264   Abstract

Synoptic climatology has a long history of research where weather data are aggregated and composited to gain a better understanding of atmospheric effects on non-atmospheric variables. This has resulted in an applied scientific discipline that yields methods and tools designed for applications across disciplinary boundaries. The spatial synoptic classification (SSC) is an example of such a tool that helps researchers bridge methodological gaps between disciplines, especially those studying weather effects on human health. The SSC has been applied in several multi-discipline projects, and it appears that there is ample opportunity for growth into new topical areas. Likewise, there is opportunity for the SSC network to be expanded across the globe, especially into mid-latitude locations in the Southern Hemisphere. There is some question of the utility of the SSC in tropical locations, but such decisions must be based on the actual weather data from individual locations. Despite all of the strengths and potential uses of the SSC, there are some research problems, some locations, and some datasets for which it is not suitable. Nevertheless, the success of the SSC as a cross-disciplinary method is noteworthy because it has become a catalyst for collaboration.

Vanos, JK, Middel A, McKercher G, Kuras ER, Ruddell B.  2016.  Hot playgrounds and children's health: a multiscale analysis of surface temperatures in Arizona, USA. Landscape and Urban Planning. 146:29-42. Abstract
Cakmak, S, Hebbern C, Vanos J, Crouse DL, Burnett R.  2016.  Ozone exposure and cardiovascular-related mortality in the Canadian Census Health and Environment Cohort (CANCHEC) by spatial synoptic classification zone. Environmental Pollution. 214:589-599.: Elsevier Abstract
Hondula, DM, Balling RC, Vanos JK, Georgescu M.  2015.  Rising Temperatures, Human Health, and the Role of Adaptation. Current Climate Change Reports. 1:144-154.   10.1007/s40641-015-0016-4   Abstract

There is near consensus in the scientific community that humans will experience higher future temperatures due to the ongoing accumulation of greenhouse gases in the atmosphere. The human response to this climatic change, particularly if accompanied by a surge in extreme heat events, is a key topic being addressed by scientists across many disciplines. In this article, we review recent (2012–2015) research on human health impacts of observed and projected increases in summer temperature. We find that studies based on projected changes in climate indicate substantial increases in heat-related mortality and morbidity in the future, while observational studies based on historical climate and health records show a decrease in negative impacts during recent warming. The discrepancy between the two groups of studies generally involves how well and how quickly humans can adapt to changes in climate via physiological, behavioral, infrastructural, and/or technological adaptation, and how such adaptation is quantified.