A feasibility study for assessing building occupants' indoor air quality expectations compared to nationally recognized standards

Indoor Air Quality (IAQ) can have significant implications for health, productivity, job performance, and operating cost. Professional experience in the field of indoor air quality suggests that high expectations (better than nationally established standards) (American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE)) of workplace indoor air quality lead to increase air quality complaints. To determine whether there is a positive association between expectations and indoor air quality complaints, a one-time descriptive and analytical cross-sectional pilot study was conducted. Area Safety Liaisons (n = 330) at University of Texas Health Science Center – Houston were asked to answer a questionnaire regarding their expectations of four workplace indoor air quality indicators i.e., (temperature, relative humidity, carbon dioxide, and carbon monoxide) and if they experienced and reported indoor air quality problems. A chi-square test for independence was used to evaluate associations among the variables of interest. The response rate was 54% (n = 177). Results did not show significant associations between expectation and indoor air quality. However, a greater proportion of Area Safety Liaisons who expected indoor air quality indicators to be better than the established standard experienced greater indoor air quality problems. Similarly, a slightly higher proportion of Area Liaisons who expected indoor air quality indicators to be better than the standard reported greater indoor air quality complaints. ^ The findings indicated that a greater proportion of Area Safety Liaisons with high expectations (conditions that are beyond what is considered normal and acceptable by ASHRAE) experienced greater indoor air quality discomfort. This result suggests a positive association between high expectations and experienced and reported indoor air quality complaints. Future studies may be able to address whether the frequency of complaints and resulting investigations can be reduced through information and education about what are acceptable conditions.^

Risk and resiliency: The untold story of youth in military families

Background: Risky sexual behaviors have been shown to increase the risk of unintended pregnancy and sexually transmitted infections (STIs) among youth. Youth in military families may be especially at risk for engaging in risky sexual behaviors because they are exposed to factors that are unique to the military culture, such as multiple relocations and parental deployment. However, data on sexual behaviors among military-dependent youth are limited and few studies have examined how these factors influence the sexual behaviors among youth. Purpose: The purpose of this dissertation was to estimate the prevalence of risky sexual behaviors among military-dependent youth and to describe how military factors may influence their sexual behaviors. Methods: Youth, aged 15–19 years, who attended a military health facility in the southern United States between June 2011 and September 2011 were recruited to complete a short, paper-based survey (N= 208, males and females) and to participate in an in-depth interview (N = 25, females). For quantitative data, prevalence estimates were computed and chi-square analyses were conducted. Logistic regression analyses were also conducted, adjusting for age, gender, and parents' duty status. For qualitative data, thematic coding of transcribed interviews was performed. Common and unique themes were examined across participants' experiences. Results: Over half of the youth was sexually experienced (53.7%). Parental deployment and number of relocations were significantly associated with having had sex in the past 3 months; however no significant associations were found between these military factors and other sexual behaviors. Although some youth felt that being a military-dependent had negatively impacted their sexual decisions, most believed the military experience had little influence on their sexual decisions. Most youth in military families also perceived having higher parental expectations to avoid risky behaviors, in general, than youth in civilian families. Conclusions: The majority of military-dependent youth are sexually experienced; however, individual and parental factors may have a greater role in sexual initiation among youth than military stressors do. The findings highlight the need for implementation of evidence-based strategies to prevent teen pregnancy and STIs at military installations. Future studies with larger sample sizes are needed to further explore how youth may cope with these military factors and the impact of parental factors on the sexual behaviors of youth.^

The assumptions and effects of conservative procedures in low -dose risk assessment for setting safety standards

Conservative procedures in low-dose risk assessment are used to set safety standards for known or suspected carcinogens. However, the assumptions upon which the methods are based and the effects of these methods are not well understood.^ To minimize the number of false-negatives and to reduce the cost of bioassays, animals are given very high doses of potential carcinogens. Results must then be extrapolated to much smaller doses to set safety standards for risks such as one per million. There are a number of competing methods that add a conservative safety factor into these calculations.^ A method of quantifying the conservatism of these methods was described and tested on eight procedures used in setting low-dose safety standards. The results using these procedures were compared by computer simulation and by the use of data from a large scale animal study.^ The method consisted of determining a "true safe dose" (tsd) according to an assumed underlying model. If one assumed that Y = the probability of cancer = P(d), a known mathematical function of the dose, then by setting Y to some predetermined acceptable risk, one can solve for d, the model's "true safe dose".^ Simulations were generated, assuming a binomial distribution, for an artificial bioassay. The eight procedures were then used to determine a "virtual safe dose" (vsd) that estimates the tsd, assuming a risk of one per million. A ratio R = ((tsd-vsd)/vsd) was calculated for each "experiment" (simulation). The mean R of 500 simulations and the probability R $<$ 0 was used to measure the over and under conservatism of each procedure.^ The eight procedures included Weil's method, Hoel's method, the Mantel-Byran method, the improved Mantel-Byran, Gross's method, fitting a one-hit model, Crump's procedure, and applying Rai and Van Ryzin's method to a Weibull model.^ None of the procedures performed uniformly well for all types of dose-response curves. When the data were linear, the one-hit model, Hoel's method, or the Gross-Mantel method worked reasonably well. However, when the data were non-linear, these same methods were overly conservative. Crump's procedure and the Weibull model performed better in these situations. ^