Health hazards due to exposure to methyl tertiary-butyl ether [MTBE] among groups of Egyptian workers

Methyl tertiary Butyl Ether [MTBE] has been used as a gasoline additive, since at least 20 years, in many countries. It is usually used to increase octane levels and more recently to reduce the levels of carbon monoxide emissions. The present work aimed at investigating the possible health hazards due to occupational exposure to methyl tertiary ethyl ether [MTBE]. Forty-five workers exposed to MTBE during their work; 17 of them from the Cairo Petroleum Refinery Company and 28 from several gasoline stations [n= 28], chosen on a stratified random sample basis. All workers included in the present work were interviewed, they were informed about the nature of the study, and subsequently consented to have additional blood withdrawn for blood count, biochemical [hepato-renal function tests], as well as chromosomal study of their peripheral blood lymphocytes. Clinical examination was done, stressing the condition of the chest, heart, liver, kidneys and skin. About 46% of the studied workers had chest, ear, nose and throat, as well as other manifestations. Haematological, hepatic and renal function test results were elicited among the tested group. However, on performing the haematological and biochemical investigation, pre- and post- exposure, statistically insignificant differences were elicited, except for RBCs [less on post- exposure] and creatinine [more on post- exposure]. In addition, the group belonging to the refinery were more affected in their haematological, biochemical and chromosomal aberrations' parameters, than their colleagues at the gasoline pumping stations, and the differences were statistically significant in relation to haemoglobin, SGOT, SGPT, and blood urea levels. Mild to moderate chromosomal abnormalities affected 44% of the examined workers, in forms of: gaps, breaks, deletions, isogaps, isobreaks, centromere separation, dicentrics, and polyploidy. Workers employed in measuring the MTBE levels at the refinery company, i.e. measurers, were more affected in their haematological, biochemical and chromosomal aberrations' parameters, than their colleagues, and the differences were statistically significant in relation to haemoglobin, SGOT, and total number of chromosomal aberrations. Different symptoms were more complained of among the measurers than among the others. The study revealed many adverse effects, which strongly suggest the relation with either acute or chronic consequences of the new gasoline additive MTBE. The onset of such manifestation was observed by the complained workers following the start of addition of MTBE, about 2 years ago. The study also revealed mild to moderate chromosomal aberrations among 44% of the exposed workers. Occupational health surveillance system should be followed on periodic basis. Testing for the quality and function of blood, hepatic, renal, cytogenetic systems are among the primary targets of the proposed system. First aid measures are to be provided in workplaces where possible exposure to MTBE exists. Addition of the Threshold Limit Value for MTBE to the Egyptian legislative decree concerned with limit values for chemicals, as well as adding the probable health consequences due to MTBE occupational exposure to the Egyptian list for occupational illness. Continuous monitoring of MTBE in workplace environment, as well as their related metabolites [in biological samples], should be a routine procedure

Environmental and respiratory health assessment of workers chronically exposed to coal dust in an Egyptian Coal-Mine at North Sinai

The present work aims at evaluating the respiratory effects among a group of Egyptian coalworkers chronically exposed to coal dust. The present work comprised 228 coal workers employed for durations ranging from 0.2 to 33 years in various sections of a coal mine, located at north Sinai of Egypt. The workers were subjected to a questionnaire comprising full personal, present, past, family and occupational histories, clinical examination, chest X-ray, ventilatory function tests, and assay of immunoglobulins M, G, and E. Total, respirable and non-respirable dust samples were collected and analysed from different workplace air. Personal total, respirable and non-respirable dust samples being collected from different workplace air proved to exceed the TLV, especially at the feeding tunnel and the washing box. The clinical study revealed mild to moderate affection of the ventilatory function parameters, especially for those related to small and medium size airways. Clinically, positive cases were about 40% of the studied workers, and radiologically, abnormal chest X-rays affected about 25% of the surveyed personnel. An increased incidence of obstructive and combined ventilatory defects was noticed with longer duration of employment. The same was noticed with abnormal findings elicited by the chest X-rays, especially mentioning suspected interstitial pulmonary fibrosis [IPF]. Workers at the underground sites had significant higher incidence of chest symptoms, abnormally higher values of IgG and IgE, more cases with broncho-vascular markings and JPF than their colleagues working on the ground. Clinically positive workers had more abnormal chest X ray findings and about 71% of them had COPD, irrespective to the place of work. Positive cases were also correlated well with abnormal IgG and IgE. The study pointed out the presence of definite exposure to coal dust, higher than the recommended TLV, in different sections at Maghara coal mine. The clinical study revealed adverse respiratory effects among coal-workers, which strongly suggest the relation with chronic coal dust exposure. Smoking has significant influence on the development of chest symptoms elicited among the studied workers. Adopting pre-placement and periodic medical examinations, provision of training, and supplying coal-workers with suitable protective equipment. Addition of "Coal dust Exposure and Consequent Effects" to the Egyptian list of occupational diseases. Continuous monitoring of coal dust should be a routine procedure

Pesticides and asthma

In this study we try to prove and evaluate the acute and chronic effects of pesticides on respiratory system among pesticide applicators. They were applicators of different types of pesticides [organophosphates, carbarnates, pyrethroides and or-ganochlorine] living in an Egyptian village [150 Km south to Cairo]. Respiratory symptoms were reported in about 66.5% of the applicators and only in 33.4% of controls [highly significant p < 0.01]. Chest examination revealed that 21.7% of the applicators and 11.4% of the control subjects had respiratory signs. Analysis of the ventilatory function results showed a significant ventilatory defect [p < 0.05] among applicators when compared to the control, these were in the form of obstructive defects [doubled] and restrictive defect [5 folds increase]. The relation between the duration of exposure among applicatos and the ventilatory functions showed that the more they were exposed to pesticides the higher the incidence of ventilatory function changes. The challenge test was done to 38 applicators and 63 control subjects, with 39.5% +ve in applicators and only 17.9% in control, and the result was significant. Also, the serum cortisol level and cholinesterase activity were more depressed among applicators than in controls. We concluded that people with chest problems, especially asthma and COPD, should avoid exposure to pesticides. Challenge test with methacholine should be done as screening test to all applicators before exposure and positive subjects should be excluded