Ann L. Fredrickson

Outdoor, Indoor, and Personal Exposure to VOCs in Children

We measured volatile organic compound (VOC) exposures in multiple locations for a diverse population of children who attended two inner-city schools in Minneapolis, Minnesota. Fifteen common VOCs were measured at four locations: outdoors (O), indoors at school (S), indoors at home (H), and in personal samples (P). Concentrations of most VOCs followed the general pattern O ≈ S < P ≤ H across the measured microenvironments. The S and O environments had the smallest and H the largest influence on personal exposure to most compounds. A time-weighted model of P exposure using all measured microenvironments and time–activity data provided little additional explanatory power beyond that provided by using the H measurement alone. Although H and P concentrations of most VOCs measured in this study were similar to or lower than levels measured in recent personal monitoring studies of adults and children in the United States, p-dichlorobenzene was the notable exception to this pattern, with upper-bound exposures more than 100 times greater than those found in other studies of children. Median and upper-bound H and P exposures were well above health benchmarks for several compounds, so outdoor measurements likely underestimate long-term health risks from children’s exposure to these compounds.

Children's exposure to volatile organic compounds as determined by longitudinal measurements in blood

Blood concentrations of 11 volatile organic compounds (VOCs) were measured up to four times over 2 years in a probability sample of more than 150 children from two poor, minority neighborhoods in Minneapolis, Minnesota. Blood levels of benzene, carbon tetrachloride, trichloroethene, and m-/p-xylene were comparable with those measured in selected adults from the Third National Health and Nutrition Examination Survey (NHANES III), whereas concentrations of ethylbenzene, tetrachloroethylene, toluene, 1,1,1-trichloroethane, and o-xylene were two or more times lower in the children. Blood levels of styrene were more than twice as high, and for about 10% of the children 1,4-dichlorobenzene levels were ≥10 times higher compared with NHANES III subjects. We observed strong statistical associations between numerous pairwise combinations of individual VOCs in blood (e.g., benzene and m-/p-xylene, m-/p-xylene and o-xylene, 1,1,1-trichloroethane and m-/p-xylene, and 1,1,1-trichloroethane and trichloroethene). Between-child variability was higher than within-child variability for 1,4-dichlorobenzene and tetrachloroethylene. Between- and within-child variability were approximately the same for ethylbenzene and 1,1,1-trichloroethane, and between-child was lower than within-child variability for the other seven compounds. Two-day, integrated personal air measurements explained almost 79% of the variance in blood levels for 1,4-dichlorobenzene and approximately 20% for tetrachloroethylene, toluene, m-/p-xylene, and o-xylene. Personal air measurements explained much less of the variance (between 0.5 and 8%) for trichloroethene, styrene, benzene, and ethylbenzene. We observed no significant statistical associations between total urinary cotinine (a biomarker for exposure to environmental tobacco smoke) and blood VOC concentrations. For siblings living in the same household, we found strong statistical associations between measured blood VOC concentrations.

Indoor Air Quality in Two Urban Elementary Schools—Measurements of Airborne Fungi, Carpet Allergens, CO2, Temperature, and Relative Humidity

This article presents measurements of biological contaminants in two elementary schools that serve inner city minority populations. One of the schools is an older building; the other is newer and was designed to minimize indoor air quality problems. Measurements were obtained for airborne fungi, carpet loadings of dust mite allergens, cockroach allergens, cat allergens, and carpet fungi. Carbon dioxide concentrations, temperature, and relative humidity were also measured. Each of these measurements was made in five classrooms in each school over three seasons—fall, winter, and spring. We compared the indoor environments at the two schools and examined the variability in measured parameters between and within schools and across seasons. A fixed-effects, nested analysis was performed to determine the effect of school, season, and room-within-school, as well as CO2, temperature and relative humidity. The levels of all measured parameters were comparable for the two schools. Carpet culturable fungal concentrations and cat allergen levels in the newer school started and remained higher than in the older school over the study period. Cockroach allergen levels in some areas were very high in the newer school and declined over the study period to levels lower than the older school. Dust mite allergen and culturable fungal concentrations in both schools were relatively low compared with benchmark values. The daily averages for temperature and relative humidity frequently did not meet ASHRAE guidelines in either school, which suggests that proper HVAC and general building operation and maintenance procedures are at least as important as proper design and construction for adequate indoor air quality. The results show that for fungi and cat allergens, the school environment can be an important exposure source for children.

A school-based strategy to assess children's environmental exposures and related health effects in economically disadvantaged urban neighborhoods

The School Health Initiative: Environment, Learning, Disease (SHIELD) study is a novel school-based investigation of childrens environmental health in economically disadvantaged urban neighborhoods of Minneapolis. This article describes the study design and summarizes lessons learned about recruiting and monitoring this historically understudied population. The SHIELD study focused on measuring childrens exposures to multiple environmental stressors [volatile organic chemical (VOCs), environmental tobacco smoke, allergens, bioaerosols, metals, pesticides, polychlorinated biphenyl (PCB), phthalates] and exploring related effects on respiratory health (e.g., lung function) and learning outcomes (e.g., standardized test scores, academic achievement). It involved intensive exposure monitoring, including environmental measurements inside and outside the childrens schools and inside their homes, personal measurements with passive dosimeters worn by the children, and biological marker measurements in blood and urine. The SHIELD participants comprised a stratified random sample of 153 “index” children and 51 of their siblings enrolled in grades 2–5 at two adjacent elementary schools. The Minneapolis Public Schools (MPS) assisted with identifying, contacting, recruiting, and monitoring this population, which traditionally is difficult to study because families/children are highly mobile, speak a diversity of languages, frequently do not have a telephone, endure economic hardships, often do not trust researchers, and have a spectrum of unconventional lifestyles and living arrangements. Using a school-based approach, the overall SHIELD enrollment (response) rate was 56.7%, with a wide disparity between English-speaking (41.7%) and non-English-speaking (71.0%) families/children. Most children remained involved in the study through both monitoring sessions and exhibited an acceptable degree of compliance with study protocols, including providing blood and urine samples. Results indicate that it is both practical and affordable to conduct probability-based exposure studies in this population, but that it is also important to improve our understanding of factors (e.g., cultural, economic, psychological, social) affecting the willingness of families/children to participate in such studies, with special emphasis on developing cost-effective recruitment methods.

Competencies most valued by employers--Implications for master's-prepared occupational health nurses.

Educational institutions seek to prepare students to compete for positions in the workplace with a competency-based education. Employers are important stakeholders in the preparation of occupational health nurses. Competencies considered most valuable by employers will affect their hiring decisions. This study identifies competencies valued by employers in the workplace.

Crosscutting competencies for occupational health and safety professionals

A change from a quarter system to a semester system presented a convenient opportunity for faculty at the Midwest Center for Occupational Health and Safety (a 27-year-old National Institute for Occupational Safety and Health-sponsored education and research center) to evaluate the current curriculum. As part of this process faculty identified both individual and crosscutting competencies for four programs: Occupational Medicine, Occupational Health Nursing, Industrial Hygiene, and Occupational Injury Epidemiology and Control. Faculty identified potential competency sets using published literature, course objectives, and content summaries. Common themes, termed crosscutting competencies, were identified. Seventy program graduates (58%) responded to a survey designed to assess the value of, and proficiency in, these competencies based on their postgraduation job experience. All 29 crosscutting competencies were rated as valuable or very valuable by respondents in each of the four programs. There was less agreement between respondents in proficiency ratings, with 24 of 29 competencies rated either proficient or very proficient. Comparing value and proficiency provided an opportunity to further refine the curriculum and a model for enhancing the skills, knowledge, and attitudes of future environmental and occupational health professionals. With further testing, we propose this set of crosscutting competencies be considered for adoption as a set of interdisciplinary core competencies for Occupational Health and Safety professionals.

Graduate proficiency assessment using a competency-based learning model

Objective: The goal of this study was to evaluate and compare occupational health and safety graduates’ perceptions of the value of and their proficiency in 29 educational competencies. Methods: A survey was mailed to 159 students graduating between 1992 and 2005. Results: Ninety-eight graduates (62% response) ranked all 29 competencies as valuable or very valuable. Graduates reported high proficiency in the competencies they most highly valued. The greatest discrepancy between value and proficiency occurred in competencies related to managing resources, programs, and personnel. Results were similar to those of a 2001 survey. Competencies identified by occupational health and safety professionals in 49 countries were very similar to those included in our set. Conclusions: We made changes in the curriculum to address graduates’ reports of low proficiency in resource, program, and personnel management.

Assessing Outcomes of Industrial Hygiene Graduate Education

To ensure that industrial hygiene professionals continue to be prepared for current and future trends, it is important to regularly assess the value of their education. Described here are the results of discussions with employers and a mailed survey of graduates. Comparisons are made with past mailed surveys of both groups. Two sets of discussions were held in late 2005 with employers of industrial hygienists and other health and safety professionals. Twenty-eight participants were asked to discuss current and future needs for professionals in their organization and economic sector, their expectations for knowledge and skills when hiring professionals, methods for finding and hiring, and the importance of ABET accreditation. At the same time, a survey was mailed to 71 industrial hygiene students graduating in the last 15 years. Respondents were asked to rank the value of and their proficiency in 42 competencies. Questions also assessed employment experience, certification, the importance of ABET accreditation, and demographic characteristics. There was a lot of agreement between the two stakeholder groups (employers and graduates) about the most important skill and knowledge areas. Most employers identified communicating effectively and exposure assessment among the most important skills, with designing and initiating research as among the least. Hazard recognition, exposure measurement principles, and personal protective equipment were the most highly ranked knowledge areas. Employers discussed the need for good “business skills” such as teamwork, communication, and project management, and the importance of problem-solving skills. Graduates reported that skills in the areas of recognition, evaluation, and control were most valuable in their first jobs and generally reported high levels of proficiency in these skill areas. There was a similar dichotomy in opinions about accreditation within each stakeholder group. The reputation of the academic program was important when making hiring decisions; accreditation became an important factor only when a programs reputation was not known. Graduates strongly supported ongoing accreditation but did not apply or attend on the basis of accreditation.