Assessment of oxidative stress among refueling workers in an Egyptian setting.

BACKGROUND: Unlike developing countries, in Egypt, gasoline is dispensed at dedicated stations by gasoline filling workers. This leads to high levels of exposure to the aromatic compounds in gasoline [principally benzene, toluene, ethyl benzene, and xylene (BTEX)] with the consequences of adverse health effects including oxidative stress. OBJECTIVE(S): To assess oxidative stress and trace metal levels among Egyptian gas filling workers. METHODS: A cross-sectional study was conducted among 50 gasoline filling station workers (exposed group) and a matched group of 50 clerical workers (non-exposed group). Trace metal levels (Cu, Zn, Fe, and Mn) and the activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured in sera of all enrolled participants using atomic absorption spectroscopy. BTEX levels were assessed in the environment of the studied gas filling stations using the MIRAN IR system. RESULTS: All the measured trace metal levels and antioxidant enzyme activities were significantly lower among the exposed workers than among the non-exposed workers. All trace metals decreased significantly in relation to SOD activity among the exposed workers, whereas only Zn and Cu decreased in relation to SOD and GPx activity among the non-exposed workers. The exposed workers did not comply with the use of the required personal protective equipment (PPE) to avoid the dangerous effects of BTEX exposure. Among BTEX components, benzene exceeded the allowable Egyptian TLV in the studied gasoline stations (110.4 mg/m3 versus 1.6 mg/m3, respectively). The hygienic effect (HE) of the BTEX pollutant mixture exceeded the allowed borderline HE in Egypt although it did not show a significant correlation with different oxidative stress biomarkers and trace metals. CONCLUSION: Exposure to BTEX at gasoline filling stations lowers the levels of antioxidant enzyme activities and trace metals due to the strong hygienic effect of BTEX. Individual protection using the proper PPE should therefore be enforced. Research assessing the need of providing refueling workers with supplements of necessary trace metals and antioxidants is warranted.

Control of occupational exposure to phenol in industrial wastewater treatment plant of a petroleum refinery in Alexandria, Egypt: An intervention application case study.

Phenol exposure is one of the hazards in the industrial wastewater treatment basin of any refinery. It additively interacts with hydrogen sulfide emitted from the wastewater basin. Consequently, its concentration should be greatly lower than its threshold limit value. The present study aimed at controlling occupational exposure to phenol in the work environment of wastewater treatment plant in a refinery by reducing phenolic compounds in the industrial wastewater basin. This study was conducted on both laboratory and refinery scales. The first was completed by dividing each wastewater sample from the outlets of different refinery units into three portions; the first was analyzed for phenolic compounds. The second and third were for laboratory scale charcoal and bacterial treatments. The two methods were compared regarding their simplicities, design, and removal efficiencies. Accordingly, bacterial treatment by continuous flow of sewage water containing Pseudomonas Aeruginosa was used for refinery scale treatment. Laboratory scale treatment of phenolic compounds revealed higher removal efficiency of charcoal [100.0(0.0) %] than of bacteria [99.9(0.013) %]. The refinery scale bacterial treatment was [99.8(0.013) %] efficient. Consequently, level of phenol in the work environment after refinery-scale treatment [0.069(0.802) mg/m(3)] was much lower than that before [5.700(26.050) mg/m(3)], with removal efficiency of [99.125(2.335) %]. From the present study, we can conclude that bacterial treatment of phenolic compounds in industrial wastewater of the wastewater treatment plant using continuous flow of sewage water containing Pseudomonas Aeruginosa reduces the workers' exposure to phenol.

Occupational safety of different industrial sectors in Khartoum State, Sudan. Part 1: Safety performance evaluation.

BACKGROUND: Safety performance evaluation enables decision makers improve safety acts. In Sudan, accident records, statistics, and safety performance were not evaluated before maintenance of accident records became mandatory in 2005. OBJECTIVE: This study aimed at evaluating and comparing safety performance by accident records among different cities and industrial sectors in Khartoum state, Sudan, during the period from 2005 to 2007. MATERIALS AND METHODS: This was a retrospective study, the sample in which represented all industrial enterprises in Khartoum state employing 50 workers or more. All industrial accident records of the Ministry of Manpower and Health and those of different enterprises during the period from 2005 to 2007 were reviewed. The safety performance indicators used within this study were the frequency-severity index (FSI) and fatal and disabling accident frequency rates (DAFR). RESULTS: In Khartoum city, the FSI [0.10 (0.17)] was lower than that in Bahari [0.11 (0.21)] and Omdurman [0.84 (0.34)]. It was the maximum in the chemical sector [0.33 (0.64)] and minimum in the metallurgic sector [0.09 (0.19)]. The highest DAFR was observed in Omdurman [5.6 (3.5)] and in the chemical sector [2.5 (4.0)]. The fatal accident frequency rate in the mechanical and electrical engineering industry was the highest [0.0 (0.69)]. Male workers who were older, divorced, and had lower levels of education had the lowest safety performance indicators. CONCLUSION: The safety performance of the industrial enterprises in Khartoum city was the best. The safety performance in the chemical sector was the worst with regard to FSI and DAFR. The age, sex, and educational level of injured workers greatly affect safety performance.

Study of the acidic deposition phenomenon over Alexandria city.

Acid deposition commonly occurs due to conversion of primary acidic pollutants (SO2 & NO2) into secondary pollutants (H2SO4 & HNO3 and their salts). The main natural sources of acid deposition in Alexandria include lightening and microbial processes. Anthropogenic sources include traffic, industrial, fuel burning, and incineration activities. Acid deposition has ecological and economic effects in addition to health effects. The objective of this study is to assess acidity of dry and wet depositions in the atmosphere of Alexandria. Dry samples were collected as settled dust using plastic jar. Wet samples were collected as rain water using polyethylene bottle. All samples were analyzed for pH, sulfates, and nitrates. The relatively high pH values observed in depositions of Alexandria city (6.95+/-0.22) and (7.14+/-0.49) for settled dust and rain water respectively indicating the conversion of the formed acids (H2SO4 & HNO3) into their salts. This explanation was confirmed by the relatively high concentrations of sulfates and nitrates. The average values were (14.3+/-4.21 g/km2/month and 20.5+/-9.5mg/L for sulfates), and (22.6+/-10.6 g/km2/month and 0.5+/-0.32 mg/L for nitrates) for settled dust and rainwater samples respectively. It can be concluded that Alexandria is a lucky city regarding acidity of the atmosphere due to its geographic, topographic, and meteorological features. Building up acid deposition monitoring network that covers all Egyptian cities to be a nucleus for African network, using new technologies that reduce emission of acid deposition precursors and alternative sources of energy, implementing and enforcing regulations and standards for major pollutants, and increasing public awareness are recommended.