James Johnston

Dr. James Johnston

Department of Public Health, Brigham Young University
orcid

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 October 2015 in Journal of the Air & Waste Management Association
Verified
Journal Article
Closed access
CSChantel Sloan
Chantel Sloan
TPTyler J. Philipp
Tyler J. Philipp
RBRebecca K. Bradshaw
Rebecca K. Bradshaw
SCSara Chronister
Sara Chronister
WBW. Bradford Barber
W. Bradford Barber
James JohnstonJames Johnston
James Johnston
Continued development of personal air pollution monitors is rapidly improving government and research capabilities for data collection. In this study, we tested the feasibility of using GPS-enabled personal exposure monitors to collect personal exposure readings and short-term daily PM2.5 measures at 15 fixed locations throughout a community. The goals were to determine the accuracy of fixed-location monitoring for approximating individual exposures compared to a centralized outdoor air pollution monitor, and to test the utility of two different personal monitors, the RTI MicroPEM V3.2 and TSI SidePak AM510. For personal samples, 24-hr mean PM2.5 concentrations were 6.93 μg/m3 (stderr = 0.15) and 8.47 μg/m3 (stderr = 0.10) for the MicroPEM and SidePak, respectively. Based on time–activity patterns from participant journals, exposures were highest while participants were outdoors (MicroPEM = 7.61 µg/m3, stderr = 1.08, SidePak = 11.85 µg/m3, stderr = 0.83) or in restaurants (MicroPEM = 7.48 µg/m3, stderr = 0.39, SidePak = 24.93 µg/m3, stderr = 0.82), and lowest when participants were exercising indoors (MicroPEM = 4.78 µg/m3, stderr = 0.23, SidePak = 5.63 µg/m3, stderr = 0.08). Mean PM2.5 at the 15 fixed locations, as measured by the SidePak, ranged from 4.71 µg/m3 (stderr = 0.23) to 12.38 µg/m3 (stderr = 0.45). By comparison, mean 24-h PM2.5 measured at the centralized outdoor monitor ranged from 2.7 to 6.7 µg/m3 during the study period. The range of average PM2.5 exposure levels estimated for each participant using the interpolated fixed-location data was 2.83 to 19.26 µg/m3 (mean = 8.3, stderr = 1.4). These estimated levels were compared with average exposure from personal samples. The fixed-location monitoring strategy was useful in identifying high air pollution microclimates throughout the county. For 7 of 10 subjects, the fixed-location monitoring strategy more closely approximated individuals’ 24-hr breathing zone exposures than did the centralized outdoor monitor. Highlights are: Individual PM2.5 exposure levels vary extensively by activity, location and time of day; fixed-location sampling more closely approximated individual exposures than a centralized outdoor monitor; and small, personal exposure monitors provide added utility for individuals, researchers, and public health professionals seeking to more accurately identify air pollution microclimates. Implications: Personal air pollution monitoring technology is advancing rapidly. Currently, personal monitors are primarily used in research settings, but could they also support government networks of centralized outdoor monitors? In this study, we found differences in performance and practicality for two personal monitors in different monitoring scenarios. We also found that personal monitors used to collect outdoor area samples were effective at finding pollution microclimates, and more closely approximated actual individual exposure than a central monitor. Though more research is needed, there is strong potential that personal exposure monitors can improve existing monitoring networks.

27 March 2017 in Annals of Occupational and Environmental Medicine
Verified
Journal Article
Open access
PDF file
SSSeshananda Sanjel
Seshananda Sanjel
SKSanjay N. Khanal
Sanjay N. Khanal
STSteven Thygerson
Steven Thygerson
WCWilliam S. Carter
William S. Carter
James JohnstonJames Johnston
James Johnston
SJSunil Kumar Joshi
Sunil Kumar Joshi
Sanjel S, et al. Ann Occup Environ Med. 2017 Mar;29(1):9. https://doi.org/10.1186/s40557-017-0165-0

30 January 2014 in Journal of Occupational and Environmental Hygiene
Verified
Journal Article
Closed access
James JohnstonJames Johnston
James Johnston
DEDennis Eggett
Dennis Eggett
MJMichele J. Johnson
Michele J. Johnson
JRJames C. Reading
James C. Reading
Pathogen transmission in the laboratory is thought to occur primarily through inhalation of infectious aerosols or by direct contact with mucous membranes on the face. While significant research has focused on controlling inhalation exposures, little has been written about hand contamination and subsequent hand-to-face contact (HFC) transmission. HFC may present a significant risk to workers in biosafety level-2 (BSL-2) laboratories where there is typically no barrier between the workers' hands and face. The purpose of this study was to measure the frequency and location of HFC among BSL-2 workers, and to identify psychosocial factors that influence the behavior. Research workers (N = 93) from 21 BSL-2 laboratories consented to participate in the study. Two study personnel measured workers' HFC behaviors by direct observation during activities related to cell culture maintenance, cell infection, virus harvesting, reagent and media preparation, and tissue processing. Following observations, a survey measuring 11 psychosocial predictors of HFC was administered to participants. Study personnel recorded 396 touches to the face over the course of the study (mean = 2.6 HFCs/hr). Of the 93 subjects, 67 (72%) touched their face at least once, ranging from 0.2-16.0 HFCs/hr. Among those who touched their face, contact with the nose was most common (44.9%), followed by contact with the forehead (36.9%), cheek/chin (12.5%), mouth (4.0%), and eye (1.7%). HFC rates were significantly different across laboratories F(20, 72) = 1.85, p = 0.03. Perceived severity of infection predicted lower rates of HFC (p = 0.03). For every one-point increase in the severity scale, workers had 0.41 fewer HFCs/hr (r = -.27, P < 0.05). This study suggests HFC is common among BSL-2 laboratory workers, but largely overlooked as a major route of exposure. Workers' risk perceptions had a modest impact on their HFC behaviors, but other factors not considered in this study, including social modeling and work intensity, may play a stronger role in predicting the behavior. Mucous membrane protection should be considered as part of the BSL-2 PPE ensemble to prevent HFC.

18 November 2020 in Atmosphere
Verified
Journal Article
Open access
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Isabella ErrigoIsabella Errigo
Isabella Errigo
Benjamin AbbottBenjamin Abbott
Benjamin Abbott
Daniel L MendozaDaniel L Mendoza
Daniel L Mendoza
LMLogan Mitchell
Logan Mitchell
SSSayedeh Sara Sayedi
Sayedeh Sara Sayedi
DWDerrek Wilson
Derrek Wilson
Air pollution causes more damage to health and economy than previously understood, contributing to approximately one in six deaths globally. However, pollution reduction policies remain controversial even when proven effective and cost negative, partially because of misunderstanding and growing mistrust in science. We used an expert assessment to bridge these research–policy divides in the State of Utah, USA, combining quantitative estimates from 23 local researchers and specialists on the human health and economic costs of air pollution. Experts estimated that air pollution in Utah causes 2480 to 8000 premature deaths annually (90% confidence interval) and decreases the median life expectancy by 1.1 to 3.6 years. Economic costs of air pollution in Utah totaled $0.75 to $3.3 billion annually, up to 1.7% of the state’s gross domestic product. Though these results were generally in line with available estimates from downscaled national studies, they were met with surprise in the state legislature, where there had been an almost complete absence of quantitative health and economic cost estimates. We discuss the legislative and personal responses of Utah policy makers to these results and present a framework for increasing the assimilation of data into decision making via regional expert assessment. In conclusion, combining quantitative assessments from local experts is a responsive and cost-effective tool to increase trust and information uptake during time-sensitive policy windows.

STSteven Thygerson
Steven Thygerson
JBJohn D. Beard
John D. Beard
MHMarion J. House
Marion J. House
RSRilee L. Smith
Rilee L. Smith
HBHunter C. Burbidge
Hunter C. Burbidge
James JohnstonJames Johnston
James Johnston
Brick workers and their families in Nepal generally live in poorly ventilated on-site housing at the brick kiln, and may be at higher risk for non-occupational exposure to fine particulate matter air pollution and subsequent respiratory diseases due to indoor and outdoor sources. This study characterized non-occupational exposure to PM2.5 by comparing overall concentrations and specific chemical components of PM2.5 inside and outside of brick workers’ on-site housing. For all samples, the geometric mean PM2.5 concentration was 184.65 μg/m3 (95% confidence interval: 134.70, 253.12 μg/m3). PM2.5 concentrations differed by kiln number (p = 0.009). Kiln number was significantly associated with 16 of 29 (55%) air pollutant, temperature, or relative humidity variables. There was not a significant interaction between kiln number and location of sample for PM2.5 (p = 0.16), but there was for relative humidity (p = 0.02) and temperature (p = 0.01). Results were qualitatively similar when we repeated analyses using indoor samples only. There was no difference in the chemical makeup of indoor and outdoor PM2.5 in this study, suggesting that outdoor PM2.5 air pollution easily infiltrates into on-site brick worker housing. Outdoor and indoor PM2.5 concentrations found in this study far exceed recommended levels. These findings warrant future interventions targeted to this vulnerable population.

30 July 2021 in Environmental Research Letters
Verified
Journal Article
Open access
PDF file
James JohnstonJames Johnston
James Johnston
JKJohn Burns Kilbride
John Burns Kilbride
GMGarrett Meigs
Garrett Meigs
CDChristopher J Dunn
Christopher J Dunn
RKRobert Kennedy
Robert Kennedy
National forests in the western United States are divided roughly in half between lands without roads managed for wilderness characteristics and lands with an extensive road system managed for multiple uses including resource extraction. We investigated the influence of these land use designations on fire ignitions, fire extent, and fire severity over the last three decades. Although roadless areas experienced fewer fire ignitions and are generally cooler, moister, and higher elevation landscapes less conducive to fire, wildfire extent was far greater in these areas than in roaded areas. An area equivalent to approximately one-third of roadless areas burned in the last three decades, while an area equivalent to less than one-fifth of roaded areas experienced fire. Most of the largest fires that have burned on national forest land in recent years began in roadless areas. Despite greater fire extent in roadless areas, there was no significant difference in fire severity between roadless areas and roaded areas after accounting for biophysical differences between these management regimes. Although fire patterns in roadless areas may pose challenges to land managers, the available evidence suggests that the greater extent of fire in roadless areas may confer resilience to these landscapes in the face of climate change.