Optimized microwave extraction for trace detection of 2,4,6-trinitrotoluene in soil samples

An optimized microwave assisted extraction method for determination of trinitrotoluene (TNT) and related compounds in soil is presented. The new enhanced method exhibits improved extraction recovery and precision as well as sample handling time. For the separation and detection gas chromatography coupled to a thermoionic probe was used achieving TNT and dinitrotoluene detection limits per injection at the femtogram level. The generated extraction recovery and precision data are given for spiked and certified soil. Determined TNT and related compounds residues in soil collected from different parts of the world are presented.     

Fourth WHO-coordinated survey of human milk for persistent organic pollutants (POPs): Belgian results

Persistent organic pollutants (POPs) are chemicals that accumulate in the food chain and are toxic to humans and wildlife. The fourth World Health Organization (WHO) survey on POP levels in human milk (2006-2009) aims to provide baseline and trend information on human exposure to POPs. So far Belgium participated in all three previous rounds (1988, 1992, 2001). Whereas the first three rounds focused on determination of dioxins and PCBs in pooled (mixed) samples, the fourth survey comprised the analyses of individual milk samples for nine "basic POPs" (chlorinated pesticides and indicator PCBs) and of pooled milk samples for "basic POPs", "advanced POPs" (dioxins and dioxin-like PCBs) and "optional POPs" (polybrominated diphenylethers [PBDEs], polybrominated dioxins and dibenzofurans [PBrDD/F], mixed halogenated dioxins and dibenzofurans [PXDD/F] and hexabromocyclododecane [HBCD]). For the Belgian participation human milk samples were collected during the summer of 2006 from 197 women between 18 and 30 years old distributed over all Belgian provinces. The individual samples were analyzed in a Belgian Laboratory for "basic" POPs. A pooled sample was made from 178 individual samples and analyzed by the WHO Reference Laboratory for the "basic, advanced and optional" POPs. The results indicate that most organochlorinated pesticides banned 25-30 years ago were below or around detection limits in Belgian human milk samples although DDE was still found at low levels in all samples. Over the last five years the levels of marker PCBs and PCDD/Fs in Belgian human milk decreased, respectively, by 58% and 39%. For some of the other emerging or older compounds recent international data are needed to allow comparison. This shows the importance of international studies as run by WHO.     

Reproductive toxicity of trenbolone acetate in embryonically exposed Japanese quail

This study was conducted to assess the effects of a one time embryonic exposure to trenbolone acetate on reproductive development and function in Japanese quail (Coturnix japonica). Embryos were exposed to either 0.05, 0.5, 5, or 50microg trenbolone or a sesame oil vehicle control at embryonic day 4. Onset of puberty, gonadal histopathology, sperm motility, cloacal gland size, and male copulatory behavior were assessed in adults. Trenbolone delayed onset of puberty in males, inhibited cloacal gland development, and reduced male reproductive behaviors. Industry laboratories have shown trenbolone acetate to be non-teratogenic in mammalian studies. Our study, however, shows that this one time in ovo exposure delayed onset of puberty in and suppressed adult copulatory behavior in quail males. These results suggest that this one time embryonic exposure to trenbolone may have disrupted development of either the central nervous system or the hypothalamic-pituitary-gonadal axis. This is the first study to demonstrate a demasculinizing effect on copulatory behavior in Japanese quail from embryonic exposure to a non-aromatizable androgenic chemical. More studies are needed to determine the mechanisms behind the observed effects.     

Changes in fall prevention training for apprentice carpenters based on a comprehensive needs assessment

Problem

Falls from heights in residential construction are common, especially among inexperienced workers.

Methods

We conducted a comprehensive needs assessment to determine gaps in the school-based apprentice carpenters' fall prevention training. A team of carpenter instructors and researchers revised the fall prevention training to fill these gaps. Apprentice evaluation and feedback guided ongoing curricular improvements.

Results

Most apprentice carpenters performed work tasks at heights prior to training and fall protection techniques were not commonly used at residential construction sites. Priorities of the revised school-based training included safe ladder habits, truss setting, scaffold use, guarding floor openings, and using personal fall arrest systems. New apprentices were targeted to ensure training prior to exposure at the workplace. We used adult learning principles to emphasize hands-on experiences. A framed portion of a residential construction site was fabricated to practice fall protection behaviors in a realistic setting. The revised curriculum has been delivered consistently and apprentice feedback has been very favorable.

Conclusions

Integration of needs assessment results was invaluable in revising the school-based carpenters apprentice fall prevention curriculum. Working closely with the instructors to tailor learning experiences has provided preliminary positive results.

Impact on Industry

The fall safety of the residential construction industry continues to lag behind commercial construction and industrial settings. The National Occupational Research Agenda includes a Strategic Goal to strengthen and extend the reach of quality training and education in the construction industry via mechanisms such as construction safety and health training needs assessments. This study demonstrates how a structured process can be used to identify and remedy gaps and improve training effectiveness. We encourage others to take steps to assess and increase the impact of training efforts directed at all residential construction professionals; including both union and non-union workers. The implications are even greater in the non-union sector where most U.S. residential work is done.     

Effects of self-esteem and gender on goal choice

The relationship between enduring or personality characteristics and goal choice has been of considerable theoretical, but little empirical interest in recent years. From an expectancy value perspective, we addressed the impact of self-esteem and gender on choice of goal difficulty level. As predicted, esteem and gender made significant contributions to the prediction of goal choice. The implications of these findings for future research in organizational settings, goal setting theory, and the relationship between goals and tasks are discussed.     

Driving self-restriction in high-risk conditions: how do older drivers compare to others?

Introduction

Many older drivers self-restrict or avoid driving under high-risk conditions. Little is known about the onset of driving self-restrictions or how widespread self-restrictions are among drivers of all ages.

Methods

The Second Injury Control and Risk Survey (ICARIS-2) was a nationwide cross-sectional, list-assisted random-digit-dial telephone survey from 2001 to 2003. National prevalence estimates and weighted percentages of those reporting driving self-restrictions were calculated. Multivariable logistic regression was used to explore associations between specific self-restrictions and age group, adjusting for other personal characteristics.

Results

More than half of all drivers reported at least one driving self-restriction. The most commonly reported restriction was avoidance of driving in bad weather (47.5%), followed by at night (27.9%) and on highways or high-speed roads (19%). A greater percentage of young adult women (18-24 years) reported self-restricting in bad weather compared to women in other age groups, and the percentage of drivers self-restricting at night, in bad weather, and on highways or high-speed roads increased steeply after age 64. We found that women, those in low income groups, and those who had driven low annual mileage were more likely to self-restrict.

Conclusions

In addition to assessing self-restrictions among older drivers, a new finding from our study is that self-restrictions are also quite prevalent among younger age groups. Driving self-restrictions may be better understood as a spectrum across ages in which drivers’ reasons for restriction change.

Impact on industry

Future research on the ability of driving self-restrictions to reduce actual crash risk and prevent injuries is needed.     

Factors influencing private and public environmental protection behaviors: results from a survey of residents in Shaanxi, China

Currently one of the largest and most rapidly developing countries, China also has some of the world's most severe environmental problems. China will most likely need to use all of the potential major strategies currently available to solve the country's huge environmental challenges, including promoting individual conservation behavior through educational campaigns and encouraging public environmental advocacy. This paper summarized the findings of a survey of 347 residents of Shaanxi province on environmental attitudes and behaviors. The survey found generally high levels of environmental knowledge and high recognition of the seriousness of environmental issues, moderate levels of individual actions supporting environmental resource conservation and low levels of public environmental behaviors, particularly for organized public advocacy. Further analysis indicated that the perceived importance of environmental protection is the most important factor influencing individual environmental resource conservation, but not public advocacy behaviors. Implications for environmental campaigns are discussed.