Michael Yost

Michael Yost
University of Washington Seattle | UW · Department of Environmental and Occupational Health Sciences

About

178
Publications
23,328
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
4,937
Citations

Publications

Publications (178)
Article
Full-text available
Background Pesticides play an important role in protecting the food supply and the public’s health from pests and diseases. By their nature, pesticides can be toxic to unintended target organisms. Changing winds contribute to pesticide drift— the off-target movement of pesticides—and can result in occupational and bystander illness. Methods We sys...
Article
Full-text available
The Mobile ObserVations of Ultrafine Particles study was a two-year project to analyze potential air quality impacts of ultrafine particles (UFPs) from aircraft traffic for communities near an international airport. The study assessed UFP concentrations within 10 miles of the airport in the directions of aircraft flight. Over the course of four sea...
Article
Pesticide spray drift represents an important exposure pathway that may cause illness among orchard workers. To strike a balance between improving spray coverage and reducing drift, new sprayer technologies are being marketed for use in modern tree canopies to replace conventional axial fan airblast (AFA) sprayers that have been used widely since t...
Article
The benchmark dose has been frequently recommended for the creation of points of departure for regulatory dose limits, but many regulations, including pesticide risk assessment and registration in the United States, continues to rely on NOAEL methods as the OECD toxicological standard methods recommend. This study used data from studies in support...
Article
Full-text available
In Washington State, a majority of reported pesticide-related illnesses and application-related complaints involve drift. We employed real-time particle monitors (Dylos) during a series of experimental spray events investigating drift. Sections of an orchard block were randomly sprayed by an axial fan airblast sprayer, while monitors sampled partic...
Article
In Washington State, half of all pesticide-related illnesses in agriculture result from drift, the off-target movement of pesticides. Of these, a significant proportion involve workers on another farm and orchard airblast applications. We compared the spray drift exposure reduction potential of two modern tower sprayers – directed air tower (DAT) a...
Article
Full-text available
Pesticide spray drift represents an important cause of crop damage and farmworker illness, especially among orchard workers. We drew upon exposure characteristics from known human illness cases to design a series of six spray trials that measured drift from a conventional axial fan airblast sprayer operating in a modern orchard work environment. Po...
Article
Mobile monitoring and passive sampling device (PSD) monitoring are popular air pollutant measurement techniques with complementary strengths and weaknesses. This study investigates the utility of combining data from concurrent two-week mobile monitoring and PSD campaigns in Los Angeles in summer and early spring to identify sources of traffic-relat...
Article
Implementation of probabilistic analyses in exposure assessment can provide valuable insight into the risks of those at the extremes of population distributions, including more vulnerable or sensitive subgroups. Incorporation of these analyses into current regulatory methods for occupational pesticide exposure is enabled by the exposure data sets a...
Article
Full-text available
This research analyzed the relationship between extreme heat and Emergency Medical Service (EMS) calls in King County, WA, USA between 2007 and 2012, including the effect of community-level characteristics. Extreme heat thresholds for the Basic Life Support (BLS) data and the Advanced Life Support (ALS) data were found using a piecewise generalized...
Article
Objective: We evaluated the effects of ozone on respiratory-related hospital admissions in three counties in Washington State from 1990 to 2006. We further examined vulnerability to ozone by key demographic factors. Method: Using linked hospital admission and ambient monitoring data, we estimated the age-, sex-, and health insurance-stratified a...
Article
We have applied the absolute principal component scores (APCS) receptor model to on-road, background-adjusted measurements of NOx, CO, CO2, black carbon (BC), and particle number (PN) obtained from a continuously moving platform deployed over nine afternoon sampling periods in Seattle, WA. Two Varimax-rotated principal component features described...
Article
Full-text available
Background Recent studies have highlighted the increased potency of oxygen analogs of organophosphorus pesticides. These pesticides and oxygen analogs have previously been identified in the atmosphere following spray applications in the states of California and Washington.Background: Recent studies have highlighted the increased potency of oxygen a...
Article
Full-text available
Air pollution exposure prediction models can make use of many types of air monitoring data. Fixed location passive samples typically measure concentrations averaged over several days to weeks. Mobile monitoring data can generate near continuous concentration measurements. It is not known whether mobile monitoring data are suitable for generating we...
Article
Mobile monitoring has provided a means for broad spatial measurements of air pollutants that are otherwise impractical to measure with multiple fixed site sampling strategies. However, the larger the mobile monitoring route the less temporally dense measurements become, which may limit the usefulness of short-term mobile monitoring for applications...
Article
Full-text available
Exposure to excessive heat kills more people than any other weather-related phenomenon, aggravates chronic diseases, and causes direct heat illness. Strong associations between extreme heat and health have been identified through increased mortality and hospitalizations and there is growing evidence demonstrating increased emergency department visi...
Article
Diesel exhaust presents a community exposure hazard, but methods to measure internal exposure are lacking. We report results from a community-based study using 1-nitropyrene (1-NP) and its urinary metabolites as markers of exposure to traffic-related diesel particulate matter (DPM). The study participants were Tijuana, Mexico residents who commuted...
Article
Full-text available
This article presents a new methodology to potentially quantify polycyclic aromatic hydrocarbon (PAH) isomers using high-resolution time of flight aerosol mass spectrometer (HR-AMS). The fragmentation of PAHs within the HR-AMS is such that significant signal remains at the molecular ion. After quantifying the molecular ion signal and taking into ac...
Article
Full-text available
The y-axis label for Fig 5 incorrectly states mean rather than difference. The correct y-axis is “Difference of Shinyei and APS Mass (μg/m3)”. The authors have provided a corrected version of Fig 5 here. Fig 5 Bland Altman Plots (4 sensors pooled together).
Article
Full-text available
Objective: Finely resolved PM2.5 exposure measurements at the level of individual participants or over a targeted geographic area can be challenging due to the cost, size and weight of the monitoring equipment. We propose re-purposing the low-cost, portable and lightweight Shinyei PPD42NS particle counter as a particle counting device. Previous fi...
Article
Background: Large-scale animal feeding operations compromise regional air quality in the rural US through emission of pollutants, such as ammonia gas. Exposure to airborne pollution from animal feeding operations may cause pediatric asthma exacerbations in surrounding communities. Objectives: To describe spatial and temporal patterns in ambient...
Article
Full-text available
Job exposure matrices (JEMs) are tools used to classify exposures for job titles based on general job tasks in the absence of individual level data. However, exposure uncertainty due to variations in worker practices, job conditions, and the quality of data has never been quantified systematically in a JEM. We describe a methodology for creating a...
Article
Extreme heat has been associated with increased mortality, particularly in temperate climates. Few epidemiologic studies have considered the Pacific Northwest region in their analyses. This study quantified the historical (May to September, 1980-2010) heat-mortality relationship in the most populous Pacific Northwest County, King County, Washington...
Article
Full-text available
We present an update to an electric shock job exposure matrix (JEM) that assigned ordinal electric shocks exposure for 501 occupational titles based on electric shocks and electrocutions from two available data sources and expert judgment. Using formal expert elicitation and starting with data on electric injury, we arrive at a consensus-based JEM....
Article
Long-term exposure to seated whole-body vibration (WBV) is one of the leading risk factors for the development of low back disorders. Professional bus and truck drivers are regularly exposed to continuous WBV, since they spend the majority of their working hours driving heavy vehicles. This study measured WBV exposures among professional bus and tr...
Article
Abstract Increased morbidity and mortality have been associated with extreme heat events, particularly in temperate climates. Few epidemiologic studies have considered the impact of extreme heat events on hospitalization rates in the Pacific Northwest region. This study quantifies the historic (May to September 1990-2010) heat-morbidity relationshi...
Article
Washington state dairy producers were surveyed to determine pest and parasite prevalence and range of current pest management strategies. Nearly all respondents reported treating their cattle or premises for flies, while 62% reported treating their animals for external parasites. Use of pyrethroid and pyrethrins insecticides was common throughout t...
Article
A mobile monitoring platform developed at the University of Washington Center for Clean Air Research (CCAR) measured 10 pollutant metrics (10 s measurements at an average speed of 22 km/hr) in two neighborhoods bordering a major interstate in Albuquerque, NM, USA from April 18-24 2012. 5 days of data sharing a common downwind orientation with respe...
Article
Full-text available
Determine protection effectiveness of 5-mil natural rubber latex (0.13-mm), 5-mil nitrile rubber (0.13-mm), and 13-mil butyl rubber (0.33-mm) glove materials against solvents present in a commonly used automotive clear coat formulation using a novel permeation panel. The latex and nitrile gloves were the type commonly used by local autobody spray p...
Article
Elevated pediatric asthma morbidity has been observed in rural US communities, but the role of the ambient environment in exacerbating rural asthma is poorly understood. To investigate associations between particulate matter less than 2.5μm in diameter (PM2.5) and pediatric asthma exacerbations in an agricultural community of Washington State. Scho...
Article
Full-text available
Although night-shift work has been associated with elevated risk of breast cancer in numerous epidemiologic studies, evidence is not consistent. We conducted a nested case-cohort study to investigate a possible association between shift work including a night shift and risk of breast cancer within a large cohort of women textile workers in Shanghai...
Article
Shipbuilding involves intensive welding activities within enclosed and confined spaces, and although ventilation is commonly used in the industry, its use and effectiveness has not been adequately documented. Workers engaged in welding in enclosed or confined spaces in two shipyards were observed for their use of ventilation and monitored for their...
Article
Full-text available
The objective of this study was to use membrane introduction mass spectrometry (MIMS), implemented on a mobile platform, in order to provide real-time, fine-scale, temporally and spatially resolved measurements of several hazardous air pollutants. This work is important because there is now substantial evidence that fine-scale spatial and temporal...
Article
Organophosphorus pesticides are some of the most widely used insecticides in the US, and spray drift may result in human exposures. We investigate sampling methodologies using the polyurethane foam passive air sampling device to measure cumulative monthly airborne concentrations of OP pesticides chlorpyrifos, azinphos-methyl, and oxygen analogs. Pa...
Article
Abstract Climate change is predicted to increase the frequency and duration of extreme-heat events and associated health outcomes. This study used data from the historical heat-health outcome relationship, and a unique prediction model, to estimate mortality for 2025 and 2045. For each one degree change in humidex above threshold, we find a corresp...
Article
A rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for determination of levels of the organophosphorus (OP) pesticides chlorpyrifos (CPF), azinphos methyl (AZM), and their oxygen analogs chlorpyrifos-oxon (CPF-O) and azinphos methyl-oxon (AZM-O) on common active air sampling matrices. XAD-2 resin and polyure...
Article
Full-text available
Modify a permeation panel to evaluate dermal protective clothing for resistance to sprayed coatings with minimal variability in spray paint loading across the test panel. Determine isocyanate protection effectiveness of natural rubber latex (5 mil or 0.13mm), nitrile rubber (5 mil or 0.13mm), and butyl rubber (13 mil or 0.33mm) glove materials agai...
Article
Full-text available
ABSTRACT Dermal contact with isocyanate-based coatings may lead to systemic respiratory sensitization. The most common isocyanates found in sprayed automotive coatings are monomeric and oligomeric 1,6-hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). Most spray painters use thin (4-5 mil) latex gloves that are not effective at pr...
Article
Full-text available
Exposure to magnetic fields (MFs) is hypothesized to increase the risk of breast cancer by reducing production of melatonin by the pineal gland. A nested case-cohort study was conducted to investigate the association between occupational exposure to MFs and the risk of breast cancer within a cohort of 267,400 female textile workers in Shanghai, Chi...
Article
This research describes the design, deployment, performance, and acceptability of a novel outdoor active air sampler to provide simultaneous measurements of multiple contaminants at timed intervals for the Aggravating Factors of Asthma in Rural Environment (AFARE) study-a longitudinal cohort of 50 children in Yakima Valley, Washington. The sampler...
Article
Side-by-side active air sampling for the organophosphorus (OP) pesticide, chlorpyrifos (CPF) and its oxygen analog, chlorpyrifos-oxon (CPF-O) was conducted with two recommended air sampling matrices: OSHA Versatile Sampling (OVS) tubes with XAD-2 resin, polyurethane foam (PUF) tubes, and passive PUF deposition disks. The study compared the proporti...
Article
A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. T...
Conference Paper
Field research was conducted in the Yakima Valley region of South Central Washington State in regards to Confined Animal Feeding Operations (CAFO’s) and their effects on the surrounding community to address multiple environmental health stressors as well as citizens’ health concerns. Major CAFO operations have been known to produce toxic by-product...
Article
Full-text available
Diesel exhaust (DE) is a significant contributor to the toxicity associated with particulate matter (PM). 1-Nitropyrene (1-NP) has been used as a molecular marker for DE, and the urinary metabolites of 1-NP have been proposed as biomarkers for exposure to DE. In this study, several urinary 1-NP metabolites were evaluated for their utility as marker...
Article
The transport of mixed paint solvents through natural rubber latex (4 mil) and nitrile rubber (5 mil) gloves was evaluated after spray application of the paint formulation directly on the glove surface. Glove materials and thicknesses were those selected by the majority of spray painters in the local automobile repair industry. A flat panel contain...
Article
To evaluate a consistent association between jobs in "electric" occupations and amyotrophic lateral sclerosis (ALS), a comprehensive job exposure matrix (JEM) that includes electric shocks and magnetic fields (MF) is needed. We used incident electric shocks and electrocutions from two available data sources along with expert judgment to create a JE...
Article
Full-text available
Monomeric and oligomeric 1,6-hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI) are components of catalyst hardeners in two-part polyurethane coating systems. Exposure to these isocyanates in the collision repair industry has been associated with increased risk for work-related asthma; however their quantitation remains a challengi...
Conference Paper
Walk-in-line pedestrians crossing the U.S.-Mexico border northbound at the San Ysidro, CA Port of Entry may be at an increased risk from traffic-related pollution including elevated diesel particulate matter (DPM) exposure. DPM exposure has been associated with numerous adverse health effects, including respiratory problems and lung cancer. Pedestr...
Article
Exposures that occur in utero or during childhood have long been the cornerstone of research examining the effects of environmental agents, since these groups are considered susceptible subpopulations most likely to be impacted by toxic physical or chemical agents. Since the first reports suggesting a linkage between residential proximity to power...
Article
Full-text available
Substantial exposure to isocyanates may occur during spray painting in autobody shops, yet information is lacking on the efficacy of the protective clothing used during spray painting. We investigated the personal and workplace factors associated with painters' dermal protection use during a large-scale exposure assessment study. Survey data indica...
Article
Full-text available
Design, construct, and characterize an apparatus to evaluate dermal protective clothing for resistance to polymerizing materials. Specifically, we evaluated the permeation of the most common glove material used in automotive collision repair (0.10-0.13 mm or 4-5 mil latex) with representative isocyanate-containing clear coats. Our ultimate goal is...
Article
Anaerobic digesters provide clean, renewable energy (biogas) by converting organic waste to methane, and are a key part of China's comprehensive rural energy plan. Here, experimental and modeling results are used to quantify the net greenhouse gas (GHG) reduction from substituting a household anaerobic digester for traditional energy sources in Sic...
Article
Full-text available
Illness and mortality related to heat and worsening air quality are core public health concerns associated with climate change projections. We examined the historical relationship between age- and cause-specific mortality rates from 1980 through 2006 and heat events at the 99th percentile of humidex values in the historic period from January 1, 197...
Article
Full-text available
Using a repeated measures study design, three different seats were evaluated as 12 metropolitan bus drivers drove a standardized test route including city streets, old and new freeways, and a street segment containing 10 large speed humps. Three comparisons were made: (1) comparing seats made by different manufactures (Seats 1 and 2), (2) comparing...
Article
Full-text available
Colorimetric SWYPE pads are useful tools for identifying unpolymerized aliphatic isocyanates on a variety of surfaces. This technique has been used in autobody shops to determine the presence of hexamethylene diisocyanate and other aliphatic isocyanates that are important constituents of many automotive coatings. SWYPEs have the advantage of being...