Occupational exposure to selenium among workers in rubber tire repair shops

Selenium concentration was determined in six tire repair shops in Alexandria. Concentrations of selenium were determined in tire damages repair, electric spot heater, and buffing positions. The results obtained revealed that there was a significant difference between the concentration of selenium in tire damages repair position and its concentration in electric spot heater position [t=2.47, 0.003*]. Also, there was a significant difference between the concentrations of selenium in electric spot heater position and its concentration in buffing position [t=2.86, 0.002*]. But, the difference between the concentrations of selenium in tire damages repair and in buffing positions was not significant. Workers at rubber tire repair shops were exposed to concentrations of selenium in the range of 0.7-7.3 micro g/m 3. This range is quietly below TLV of selenium [0.2 mg/m 3], but this concentration is nearly equal to lower end of range of concentration reported to produce slight tracheobronchitis in 9 out of 62 exposed workers in a selenium rectifier plant. The present study determines the levels of selenium in the environment of rubber tire repair shops and recommends that routes of absorption of selenium other than respiratory and unlimited hours of exposure should be considered while health problems is evaluated

VOCs-enrichment factor as an indicator of IAQ and health problems in economic residences in Alexandria

Indoor air quality of 5 blocks in Alexandria was investigated. VOCs-enrichment factor [VEF], that is potentially useful in lAQ investigations was evaluated in this study. Concentrations of VOCs and CO 2 were determined for 26 units and VEF was calculated. 100 housewives were selected randomly for the study [20 from each block]. For each subject, an interview, general and systemic examination, pulmonary function tests, and radiological examination were carried out. The most frequent complaint among the study population was the nonspecific complaints [51%] followed by respiratory system complaints [34%], while 28% of the studied sample reported mental complaints. There have been many studies in residences, but few include both VOCs and CO 2 concentrations. Although VOCs concentrations vary over a large range of concentrations for indoor [0.150-2.989 mg/m 3] and for outdoor [0.123-2.975 mg/m 3], the presence of elevated VOCs indicates strong contaminating source in the building. Outdoor VOCs concentration can be quite variable reflecting vehicular, commercial, and industrial emissions. CO 2 is a crude indicator of ventilation efficiency. 65% of units had VEF of about 1 indicating that bioeffluent emissions prevail, 23% of units had VEF>5 which indicates existence of strong abiotic VOCs sources, and 12% of units had VEF < 0.3 which indicates existence of large combustion source of CO 2 Adverse health responses potentially caused by VOCs in non-industrial indoor environment are irritant, systemic, and toxic effect. In addition, symptoms such as headache, fatigue, and mental confusion are indicators of the presence of combustion products such as CO 2. The VEF is applicable to residences and the present study suggests that people suspecting a connection between their health impairment and housing conditions should be taken seriously