[Consequence analysis of toxic chemicals release from petrochemical feed and product pipelines network]

Consequence analysis of toxic chemicals releases has important influence on emergency response planning and reduction of fatalities. To determine consequences of toxic chemicals releases in petrochemical feed and product pipelines network. This was a cross-sectional study performed in Mahshahr Petrochemical Special Economic Zone [Petzone, Iran] during 2006-2007. Initially, a total number of 60 pipelines were evaluated using the chemical exposure index and the most hazardous chemicals selected for further analysis. Later, the lethal concentrations of chemicals were calculated by probit equation and local meteorological data assessed. In the end, the toxic release dispersion modeling was performed using of areal location of hazardous atmospheric program, and the fatal length for emergency response planning offered. Butadiene pipeline showed the highest chemical exposure index value however, the chlorine pipeline was found to have the most hazard distance based on life-threatening health effects of emergency response planning guideline [ERPG-3]. The LC1, LC50 and LC99 in F condition were about 703m, 413m and 248m, respectively. Determination of hazard distance and emergency response planning for chlorine pipeline based on LC1 and in F condition will supply the lowest level of fatality and highest margin of safety in areas adjacent to petrochemical feed and product pipelines network

Evaluation of 4,4-methylene diphenyl diisocyanate effects on foam producing workers of car manufacture

4, 4 - Methylendiphenyl diisocyanate[MDI], is the most widely used chemical in the manufacturing of polyurethanes [a field of plastic industries], and it is one of the major causes of the occupational asthmas. Assessing the MDI concentration in air and also evaluating the effect of this chemical on eyes, skin, respiratory and gastrointestinal systems in workers of a foam producing section in a car manufacturing company. The effects of MDI on skin, eyes, respiratory and gastrointestinal systems were evaluated in two 40-person groups of exposed and unexposed workers and the MDI concentration in air was determined. The data were analyzed using t-Student test, pair-t-test, lamda[2] test, Regression Analyze, and correlation test. MDI concentration was lower than the threshold limit value while the local ventilation and air conditioning systems were both on, however, it was higher than the expected value when both systems were switched off. Our results showed that the presence of symptoms such as coughing, smart pain and dryness of skin, and the smart pain and itching of eyes in exposed group were significantly different from those in unexposed group[P<0.05]. Some of respiratory volumes were indicative of a significant difference between exposed and unexposed groups [P<0.05]. Exposure to MDI can result in reduction of respiratory volumes while increasing the occurrence of eye, skin and respiratory symptoms