No description available.

The use of cleaning products can lead to indoor concentrations of toxic air contaminants above regulatory levels. Studies show that the use of cleaning products is related to adverse respiratory health effects in adults ranging from irritation to asthma. Yet exposure to these chemicals is poorly understood. This thesis summarizes the current state of knowledge of inhalation exposure to toxic chemicals in consumer cleaning products. A new two-compartment model that treats personal air space as distinct from bulk room air is presented. The model accounts for air exchange between the two compartments and fresh air, dynamic source characteristics (i.e., the time-varying liquid concentrations and emission rates of pollutants within a mixture), the characteristics of chemical use (e.g., how frequently a cleaning chemical is applied to a new area), and reactive chemistry with ozone. The model’s applicability is restricted by limited data available for parameterization. Key components that are missing include composition data for consumer cleaning products and activity patterns. Extensive effort went into calculating the air exchange rate between the two zones. Twelve computational fluid dynamic simulations and two model scenarios were completed. The predicted concentration in the inner-zone (Cin) was divided by the room concentration predicted by the traditional well-mixed model (Cwm). Concentration ratios (Cin/Cwm) ranged from 1.1 to 700. In terms of real cleaning events, results indicate that the beginning (where the only emission source is near the person) of events taking place in large indoor environments with high air exchange rates are the situations for which well-mixed models are most likely to fail in predicting actual exposures. / text

No description available.

No description available.

No description available.

No description available.

No description available.

Wet-work exposure has been recognized as a main risk factor for developing Irritant contact dermatitis of the hand. Duration and frequency of wet-work exposure are the key risk determinants, but there is still no reliable objective method to assess these factors in the workplace. The current study aimed to further validate a newly invented wet-work exposure monitor (WWEM) among four high risk occupational groups of hairdressers, florists, caterers and nurses. The WWEM, which consists of two similar thermocouples provides a real-time indication of the wetness of the finger by measuring the temperature changes when the finger is wet and subsequent cooling when the water evaporates from the skin. A suitable data analysis routine was constructed and direct observation was employed as the gold standard. Receiver Operating Characteristic (ROC) analysis was used to compare the results. In laboratory experiments, the most suitable wet-event threshold value, as a criterion to distinguish the wet and dry exposure periods was identified as 1.6°C (Mean+5SD of the “dry” data). Using this value sensitivity and specificity were 70% and 78%, respectively. An area under the curve (AUC) of 0.78 demonstrated a “high” accuracy for WWEM in lab experiments. Field testing in real occupational fields identified varying degrees of user acceptability and different wet-event threshold values to produce maximal sensitivity and specificity of the instrument. Among hairdressers, the WWEM showed a “moderate” accuracy at the threshold value of 1.37°C with an AUC of 0.62. For florists, the most suitable threshold value in the range of examined thresholds was 1.14°C with a “good” accuracy. Among a cohort of caterers, a threshold value of 1.6°C demonstrated a “hi gh” accuracy with an AUC of 0.72. The WWEM demonstrates the minimum value of the largest AUC for nurses. This is the minimum amount of accuracy among the four occupational groups. The figure is 0.52, achieved at a threshold value of 2.5°C. The WWEM enables the frequency and duration of wet-work exposure to be assessed in an objective manner rather than the current costly and unreliable subjective methods of direct observation and questionnaire. The results indicate that the WWEM has good sensitivity and high specificity in detecting exposure to wet-work. This device provides new experimental data on wetwork exposure and may be used in future as an educational tool to highlight the importance of wet-work exposure to both employees and employers.

No description available.

The purpose of the present study was to determine if persons who had made a recent decision would be selective in seeking information related to their decisions. Also under consideration were the explanation for any selectivity exhibited, and the explanation for any variance in the degree of selectivity manifested.