Passive air sampler as a tool for long-term air pollution monitoring: Part 2. Air genotoxic potency screening assessment

The capability of passive air sampling to be employed in the evaluation of direct genotoxicity of ambient air samples was assessed. Genotoxic effects of the total extracts from the polyurethane foam filters exposed for 28 days during a regional passive air sampling campaign were investigated. Twenty sampling sites were selected in Brno city on the area of approximately 20x20 km in October and November 2004. Brno is the second largest city of the Czech Republic, highly industrialized with approximately 370,000 of permanent inhabitants. The levels of PAHs, PCBs, and chlorinated pesticides were determined in all samples. Fraction of each extract was also assayed in the bacterial genotoxicity test using Escherichia coli sulA::lacZ. Complete dose-response relationships of the air extracts were determined. The statistical analysis showed significant correlation between observed biological effects and PAHs concentrations in samples.     

Bioassay for determining sensitivity to sulfosulfuron on seven plant species

This study presents a bioassay procedure, based on the root and shoot growth parameters, for the determination of the herbicide sulfosulfuron (1-(4,6 dimethoxypyrimidin-2-yl)-3-(2-ethylsulfonylimidazo[1,2-a]pyridin-3-ylsulfonil)urea) sensitivity on seven vegetal species. Plant response to sulfosulfuron was calculated with the equations fitted to the root growth data as a function of the logarithm of the herbicide concentration by non-linear regression and was used to calculate the doses for 10, 30 and 50% inhibition of root growth (EC10, EC30 and EC50). The results indicate that the phytotoxic effect of sulfosulfuron in all the species assayed followed the order: flax > maize > onion > vetch > lepidium sativum > tomato > barley. These species showed phytotoxicity at low levels of sulfosulfuron and flax appeared to be the most susceptible species to sulfosulfuron (0.001 mg/L).     

Evaluation of ozone-nitrogen oxides-volatile organic compound sensitivity of Cincinnati, Ohio

Ambient concentrations of ozone (O3), nitrogen oxides (NOx), total reactive nitrogen (NOy), nitric acid (HNO3), and hydrogen peroxide (H2O2) were measured during September 2003 at an urban site of Cincinnati, OH. The aim of this study was two-fold: to investigate whether O3 formation in this population exposure-type site is NOx, sensitive or volatile organic compound (VOC) sensitive and to test the practicality of using two combined observational-based methods to identify the sensitivity of O3 formation in midlevel polluted locations. The evaluation of the indicator species: NOy, O3/NOy, O3/HNO3, H2O2/ HNO3, and O3/(estimated NOx reaction products), as well as the combined hypothesis testing analysis of the weekend/weekday (WE/WD) differences of 1-hr and 8-hr average maximum O3 and of the 6:00 a.m.-9:00 a.m. average nitric oxide and NOx concentrations, show evidence that Cincinnati is likely VOC sensitive. Average WE 1-hr and 8-hr maximum O3, as well as duration of WE O3 accumulation, were not lower than the corresponding WD levels in spite of the observed significant reduction in NO, emissions on WE, a typical situation in VOC-sensitive locations. The possibility that the seasonal transition from summer to autumn could have influenced the results was also investigated through an exploratory analysis of the afternoon O3 maximum/NOx measured and of the WE/WD differences of peak O3 and morning average NO and NO, concentrations observed at this site from June through September 2003. The results suggest that a VOC-sensitive chemistry regime dominated along the summer season. The findings of this study suggest that additional reductions in regional NO, emissions in Cincinnati, a potential nonattainment area under the 8-hr O3 standard, may cause an increase in local O3. Future strategies to reduce O3 in Southwest Ohio should be further evaluated carefully. The combination of observational-based methods might provide a consistent complementary approach in the identification of the NO,-VOC sensitive characteristics of mid-to-moderate polluted urban areas.     

Evaluation of heavy metal acute toxicity and bioaccumulation in soil ciliated protozoa

Laboratory toxicity tests, using ciliated protozoa, are scarce and they have been carried out usually with freshwater species. In this study, we have analysed the acute cytotoxicity of Cd, Zn and Cu in five different strains of very common soil ciliate species (Colpoda steinii, Colpoda inflata and Cyrtolophosis elongata), which were isolated from very different soil samples (polluted or not with heavy metals). Soil ciliates are quite resistant to heavy metals pollution with regard to ciliates from other habitats. The toxicity sequence was Cd>Cu>Zn. Results from Cd+Zn mixtures indicated that Cd cytotoxicity decreases in the presence of low or moderate Zn concentrations. A broad heavy metal resistance level diversity exists among isolates of colpodid ciliates and it is seen to be a genetic feature rather than a habitat dependence. Bioaccumulation is seen to be the main mechanism involved in the metal resistance, except for Cu. For the first time in ciliates, a fluorescent method has been applied to detect Zn intracellular deposits. This methodology might be an useful tool for monitoring heavy metal pollution in soils.     

Adult-supervised practice driving for adolescent learners: The current state and directions for interventions

IntroductionThe aim of this study was to quantify and identify correlates to the amount of parent-supervised behind-the-wheel practice hours by novice teen drivers.MethodsA national survey of 945 parents of recently licensed teen drivers was conducted. Multivariate logistic regression was used to identify factors related to the number of practice hours completed.ResultsSixty-one percent of parents reported practicing 50 or more hours with their teen. Two-parent involvement was associated with more practice hours, though use of a professional driving instructor was not. Parents of teens licensed in states mandating 50 or more hours of practice driving were more likely to report at least 50 practice hours than those in states mandating 20–40 hours or in states without mandates.Impact on IndustryThe findings underscore the integral role of parents in the learning to drive process and provide further support for GDL requirements for practice hours.     

Working conditions,psychological/physical symptoms and occupational accidents. Bayesian network models

Each day thousands of workers suffer occupational accidents of varying degrees of severity. Accidents at work render workers incapable of carrying out their day to day activities, either temporarily or permanently, and they also have detrimental effects on family life, the company, and the general public. In order to reduce the occupational accident rate, it is necessary to determine the causes of those accidents. Although there are many different types of accidents, they generally stem from poor working conditions. The purpose of this study was to analyze the influence of working conditions on occupational accidents from data gathered in the VI National Survey of Working Conditions (VI NSWCs) in 2007. This survey utilized a random sample of the active population of Spain. The sample comprised 11,054 people (5917 males and 5137 females). In order to carry out the study, a probabilistic model was built using Bayesian networks. The model included the following variables: hygiene conditions, ergonomic conditions, job demands, physical symptoms, psychological symptoms, and occupational accidents. The study demonstrated that there were strong relationships between hygiene conditions and occupational accidents; it has been shown that poor hygienic conditions duplicate the probability of accident. Physical symptoms increased almost 50% due to poor ergonomic conditions. And finally, high job demands almost duplicated the psychological symptoms. The investigation also showed a high degree of interdependence between physical and psychological symptomatologies and the relationship between these and occupational accidents.     

Towards the improvement of UN N.5 test method for the characterization of substances which in contact with water emit flammable gases

This paper deals with a sensitivity analysis of main parameters affecting the measurement of the gas flowrate emitted during testing substances for their potential to emit flammables gases in dangerous quantities where in contact with water, according to the UN N.5 test procedure. UN N.5 is described in the Manual of Tests and Criteria of United Nations (part of the Orange Book) (ONU Manual of Test and Criteria, 2008), serving both applications of international transport regulations as well as classifications of dangerous substances according to Globally the Harmonized System (GHS) and the derived regulation applying in the EU known as “CLP” Regulation (Regulation (EC) No 1271/2008). The main reason that justifies the present research is that the measurement of emitted gases is highly critical in the final classification resulting from the interpretation of the test results. Moreover, that idea has been raised to adapt the UN N.5 test protocol for classifying, in the future, substances that by contact with water would emit dangerous quantities of toxic gases.Experiments have been carried out to cover the analysis of the influence of ambient temperature, overall volume of glassware, nature of aqueous media, mass sample and sample-to-liquid mass ratio, since such parameters are not fixed within any defined range in the UN N.5 test procedure. The influence of the flow rate measuring device was also considered. Results confirm that the above mentioned parameters may play a significant role to such an extent as to finally alter the final classification resulting from the testing. Guiding principles have also been derived from our measurements and observations towards an improved and more robust UN test protocol in the future.     

Validity and reliability of a job factors questionnaire related to the work tasks of physical therapists

Physical therapists engage in work tasks that expose them to occupational risk factors related to musculoskeletal disorders. Due to the gap in the literature on instruments focused on those workers, this study adapted a job factors questionnaire to physical therapists, and assessed its psychometric properties. The questionnaire was adapted and its content validity was established. The psychometric properties were evaluated among 142 physical therapists. Reliability was verified using the temporal-stability design and internal consistency. Construct validity was assessed with the known-groups technique. Test-retest results demonstrated intraclass correlation coefficients between .82 and .90 (p < .001). Cronbach's α of .91 verified the reliability of the questionnaire. The known-groups technique demonstrated a statistically significant difference on the scores of the items when physical therapists were compared to office workers. The results indicated that the adapted questionnaire had acceptable psychometric properties for assessing problematic job factors among physical therapists working in hospitals.