Southwest Center for Occupational and Environmental Health

Houston, TX, United States

Southwest Center for Occupational and Environmental Health

Houston, TX, United States
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Han I.,University of Texas Health Science Center at Houston | Han I.,Southwest Center for Occupational and Environmental Health | Symanski E.,University of Texas Health Science Center at Houston | Symanski E.,Southwest Center for Occupational and Environmental Health | And 2 more authors.
Journal of the Air and Waste Management Association | Year: 2017

Exposure to ambient particulate matter (PM) is known as a significant risk factor for mortality and morbidity due to cardiorespiratory causes. Owing to increased interest in assessing personal and community exposures to PM, we evaluated the feasibility of employing a low-cost portable direct-reading instrument for measurement of ambient air PM exposure. A Dylos DC 1700 PM sensor was collocated with a Grimm 11-R in an urban residential area of Houston Texas. The 1-min averages of particle number concentrations for sizes between 0.5 and 2.5 µm (small size) and sizes larger than 2.5 µm (large size) from a DC 1700 were compared with the 1-min averages of PM2.5 (aerodynamic size less than 2.5 µm) and coarse PM (aerodynamic size between 2.5 and 10 µm) concentrations from a Grimm 11-R. We used a linear regression equation to convert DC 1700 number concentrations to mass concentrations, utilizing measurements from the Grimm 11-R. The estimated average DC 1700 PM2.5 concentration (13.2 ± 13.7 µg/m3) was similar to the average measured Grimm 11-R PM2.5 concentration (11.3 ± 15.1 µg/m3). The overall correlation (r2) for PM2.5 between the DC 1700 and Grimm 11-R was 0.778. The estimated average coarse PM concentration from the DC 1700 (5.6 ± 12.1 µg/m3) was also similar to that measured with the Grimm 11-R (4.8 ± 16.5 µg/m3) with an r2 of 0.481. The effects of relative humidity and particle size on the association between the DC 1700 and the Grimm 11-R results were also examined. The calculated PM mass concentrations from the DC 1700 were close to those measured with the Grimm 11-R when relative humidity was less than 60% for both PM2.5 and coarse PM. Particle size distribution was more important for the association of coarse PM between the DC 1700 and Grimm 11-R than it was for PM2.5. Implications: The performance of a low-cost particulate matter (PM) sensor was evaluated in an urban residential area. Both PM2.5 and coarse PM (PM10-2.5) mass concentrations were estimated using a DC1700 PM sensor. The calculated PM mass concentrations from the number concentrations of DC 1700 were close to those measured with the Grimm 11-R when relative humidity was less than 60% for both PM2.5 and coarse PM. Particle size distribution was more important for the association of coarse PM between the DC 1700 and Grimm 11-R than it was for PM2.5. © 2017 A&WMA.


Whitworth K.W.,Southwest Center for Occupational and Environmental Health | Han I.,Southwest Center for Occupational and Environmental Health | Afshar M.,Southwest Center for Occupational and Environmental Health | Berens P.D.,Gynecology and Reproductive science | Symanski E.,Southwest Center for Occupational and Environmental Health
International Journal of Environmental Research and Public Health | Year: 2017

Communities of color or low socioeconomic status are disproportionately affected by metal exposure given spatial variability of the ambient levels of these contaminants. Despite this, there is little research characterizing metal concentrations in blood among disadvantaged populations in the U.S., especially among pregnant women who are particularly vulnerable and difficult to access. Thus, we conducted a pilot study among disadvantaged pregnant women in Houston, Texas to assess willingness to participate in key activities of an epidemiologic study and characterize exposures to 16 metals. Thirty-one women attending a Medicaid-serving prenatal clinic were included in this pilot study and completed an interviewer-administered questionnaire. We obtained and measured metal compounds in whole blood samples for 22 of these women during third-trimester prenatal visits. Median whole blood concentrations of Ni, As, Cd, and Pb were 27, 1.4, 0.6, and 6.3 µg/L, respectively. Most women were willing to participate in critical aspects of a research study, including wearing a personal air-sampling badge for 2–3 days (87.1%), receiving ultrasounds (83.9%), and providing blood draws (64.5%). Despite the small sample, our results provide evidence of women’s metal exposure and their willingness to participate in future research studies to elucidate exposure pathways and explore related health effects experienced among this population of disadvantaged pregnant women. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.


Furlan A.D.,University of Toronto | Furlan A.D.,Toronto Rehabilitation Institute | Gnam W.H.,University of Toronto | Gnam W.H.,Center for Addiction and Mental Health | And 12 more authors.
Journal of Occupational Rehabilitation | Year: 2012

Design Systematic Review. Objective To determine which intervention approaches to manage depression in the workplace have been successful and yielded value for employers in developed economies. Data Sources We searched MEDLINE, EMBASE, CINAHL, Central, PsycINFO, and Business Source Premier up to June 2010 using search terms in four broad areas: work setting, depression, intervention, and work outcomes. Study Selection Two independent reviewers selected potential articles that met the following criteria: working age individuals with mild or moderate depression; interventions or programs that were workplace-based or could be implemented and/or facilitated by the employer; inclusion of a comparator group in the analysis; outcomes of prevention, management, and recurrences of work disability or sickness absence, and work functioning. Methods Two reviewers independently reviewed each article for quality and extracted data using standardised forms. Following guidelines from the GRADE Working Group, the quality of evidence addressing each outcome was graded as high, moderate, low, or very low on the basis of six criteria: study design, risk of bias, consistency, generalisability, data precision, and economic benefit. Using this information and following Cochrane Collaboration guidelines, the findings for each intervention were summarised and key messages were developed. Results We identified ten randomised trials and two non-randomised studies from various countries and jurisdictions that evaluated a wide range of intervention practices. The evidence was graded as "very low" for all outcomes identified. Therefore, no intervention could be recommended. Conclusions To date, there is insufficient quality of evidence to determine which interventions are effective and yield value to manage depression in the workplace. © Springer Science+Business Media, LLC 2012.


Bangia K.S.,Office of Environmental Health Hazard Assessment | Symanski E.,Southwest Center for Occupational and Environmental Health | Strom S.S.,University of Houston | Bondy M.,Baylor College of Medicine
Environmental Health: A Global Access Science Source | Year: 2015

Background: Epidemiological studies have found that particulate matter is associated with increases in blood pressure. Yet, less is known about the effects of specific sources or constituents of particulate matter, such as diesel particulate matter or polycyclic aromatic hydrocarbons (PAHs). We evaluated associations between self-reported hypertension and residential air levels of diesel particulate matter and PAHs among individuals of Mexican origin living in a large inner city. Methods: The Mano a Mano cohort (established in 2001 by the University of Texas MD Anderson Cancer Center) is comprised of individuals of Mexican origin residing in Houston, Texas. Using geographical information systems, we linked modeled annual estimates of PAHs and diesel particulate matter at the census tract level from the 2002 and 2005 U.S. Environmental Protection Agency's National-Scale Air Toxics Assessment to baseline residential addresses of cohort members who enrolled from 2001 to 2003 or 2004 to 2006, respectively. For each enrollment period, we applied mixed-effects logistic regression models to determine associations between diesel particulate matter and PAHs, separately, and self-reported hypertension while adjusting for confounders and the clustering of observations within census tracts and households. Results: The study population consisted of 11218 participants of which 77 % were women. The mean participant age at baseline was 41 years. Following adjustment for age, there was a dose-dependent, positive association between PAHs and hypertension (medium exposure, adjusted odds ratio (OR)∈=∈1.09, 95 % CI: 0.88-1.36; high exposure, OR∈=∈1.40, 95 % CI: 1.01-1.94) for individuals enrolled during 2001-2003; associations were generally similar in magnitude, but less precise, following adjustment for age, gender, smoking, and BMI. No association was detected for the later period. There was no evidence of an association between residential levels of diesel particulate matter and hypertension. Conclusions: This study builds on a limited number of prior investigations of the association between ambient air levels of PAHs or diesel particulate matter and hypertension by focusing on a relatively young cohort of predominantly adult women of Mexican origin. Future analyses are warranted to explore associations in the cohort using incident hypertension when sufficient data become available and to further examine associations between specific chemical constituents of particulate matter and hypertension in this and other populations. © 2015 Bangia et al.


Wendt J.K.,Southwest Center for Occupational and Environmental Health | Wendt J.K.,University of Houston | Symanski E.,Southwest Center for Occupational and Environmental Health | Symanski E.,University of Houston | And 6 more authors.
Environmental Research | Year: 2014

Objective: We investigated associations of short-term changes in ambient ozone (O3), fine particulate matter (PM2.5) and nitrogen dioxide (NO2) concentrations and the timing of new-onset asthma, using a large, high-risk population in an area with historically high ozone levels. Methods: The study population included 18,289 incident asthma cases identified among Medicaid-enrolled children in Harris County Texas between 2005-2007, using Medicaid Analytic Extract enrollment and claims files. We used a time-stratified case-crossover design and conditional logistic regression to assess the effect of increased short-term pollutant concentrations on the timing of asthma onset. Results: Each 10ppb increase in ozone was significantly associated with new-onset asthma during the warm season (May-October), with the strongest association seen when a 6-day cumulative average period was used as the exposure metric (odds ratio [OR]=1.05, 95% confidence interval [CI], 1.02-1.08). Similar results were seen for NO2 and PM2.5 (OR=1.07, 95% CI, 1.03-1.11 and OR=1.12, 95% CI, 1.03-1.22, respectively), and PM2.5 also had significant effects in the cold season (November-April), 5-day cumulative lag (OR=1.11. 95% CI, 1.00-1.22). Significantly increased ORs for O3 and NO2 during the warm season persisted in co-pollutant models including PM2.5. Race and age at diagnosis modified associations between ozone and onset of asthma. Conclusion: Our results indicate that among children in this low-income urban population who developed asthma, their initial date of diagnosis was more likely to occur following periods of higher short-term ambient pollutant levels. © 2014 Elsevier Inc.


PubMed | Southwest Center for Occupational and Environmental Health, University of Houston, Office of Environmental Health Hazard Assessment and Baylor College of Medicine
Type: | Journal: Environmental health : a global access science source | Year: 2015

Epidemiological studies have found that particulate matter is associated with increases in blood pressure. Yet, less is known about the effects of specific sources or constituents of particulate matter, such as diesel particulate matter or polycyclic aromatic hydrocarbons (PAHs). We evaluated associations between self-reported hypertension and residential air levels of diesel particulate matter and PAHs among individuals of Mexican origin living in a large inner city.The Mano a Mano cohort (established in 2001 by the University of Texas MD Anderson Cancer Center) is comprised of individuals of Mexican origin residing in Houston, Texas. Using geographical information systems, we linked modeled annual estimates of PAHs and diesel particulate matter at the census tract level from the 2002 and 2005 U.S. Environmental Protection Agencys National-Scale Air Toxics Assessment to baseline residential addresses of cohort members who enrolled from 2001 to 2003 or 2004 to 2006, respectively. For each enrollment period, we applied mixed-effects logistic regression models to determine associations between diesel particulate matter and PAHs, separately, and self-reported hypertension while adjusting for confounders and the clustering of observations within census tracts and households.The study population consisted of 11218 participants of which 77% were women. The mean participant age at baseline was 41 years. Following adjustment for age, there was a dose-dependent, positive association between PAHs and hypertension (medium exposure, adjusted odds ratio (OR)=1.09, 95% CI: 0.88-1.36; high exposure, OR=1.40, 95% CI: 1.01-1.94) for individuals enrolled during 2001-2003; associations were generally similar in magnitude, but less precise, following adjustment for age, gender, smoking, and BMI. No association was detected for the later period. There was no evidence of an association between residential levels of diesel particulate matter and hypertension.This study builds on a limited number of prior investigations of the association between ambient air levels of PAHs or diesel particulate matter and hypertension by focusing on a relatively young cohort of predominantly adult women of Mexican origin. Future analyses are warranted to explore associations in the cohort using incident hypertension when sufficient data become available and to further examine associations between specific chemical constituents of particulate matter and hypertension in this and other populations.

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