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العنوان
Study of the Effect of Exposure to Cotton and Flax Dust on Blood Histamine
الناشر
Farrag M. Omran
المؤلف
Omran,Farrag M.
هيئة الاعداد
مشرف / مدبولى نوير
مشرف / ماهر ميشيل
مشرف / حسن عبدالقادر
باحث / فرج عمران
الموضوع
Occupational Health Industrial Medicine
تاريخ النشر
1980
عدد الصفحات
96 p.
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
المهن الصحية
تاريخ الإجازة
1/1/1980
مكان الإجازة
جامعة الاسكندريه - المعهد العالى للصحة العامة - Public Health
الفهرس
Only 14 pages are availabe for public view

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Abstract

The acute reversible bronchoconstriction encountered following inhalati?n of cotton and flax dusts has been explained . by pharmacological and/or antigenic liberation of histamine. in the lungs of exposed workers, especially in the first day of the jweek where more histamine is accumulated in the lung tissue ! tduring the week-end. , ~ 1e~lanation to the chronic response to dust exposure~ ..~ ~ It has been anticipated that the histamine released in the However, it has been hard to implicate such . . .lungs of exposed worke-rs is translocated into their blood streams land, consequently, raising their blood histamine levels. ~antime, such histamine may. be subjected to metabolism. In the The difference in the rate of histamine release and histamine meta­ bolism among the individual workers might, thus, explain the individuals’ selectively in the development of byssinosis. This study has been conducted to evaluate the role of histamine in the etiology of byssinosis through the investigation .-of blood histamine in workers with different respiratory diagnosis mo has been exposed to cotton and flax dusts for different levels of dust concentrations and durations. Blood samples were collect­ ed from 600 workers before the first work shift after the week­end, after two hours of dust exposure at the first work shift of the week or on the second work day, as well as from 5’0 control subjects, and analyzed f9r histamine. Results have indicated that the blood histamine is signi­ Ificantly higher in all exposed workers, whe ther byss inotics or free from any respiratory symtoms, than in control subjects. ’The histamine increase occurs at very high rate at the first years of expos ure, and is affected to’ a certain extent by the level of Idustiness; however, is higher in workers exposed to cotton dust than in those exposed to similar concentrations of flax dus t, and is mostly negligible in workers exposed to cotton-seed dust. The Ihistamine levels in blood show further significant increase upon Go iexposure to dust in the first shift after the week-end and are reduced on the second day of exposure. Moreover, the reduction oocurs to different extents in workers with different diagndsis; being significant in only the workers who are free from any respiratory symptoms. In workers exposed continuously to cotton dust, all the levels of blood histamine are considerably lower than in the matching workers I groups who have a week-end inter­ ruption. These results led to the conclusions that: 1. The process of histamine formation in the lungs of workers exposed to cotton and flax dusts is potentiated by agentCs) present in the dust. Such potentia ting effect is proportional to the amount of -inhaled agentCs), viz: concentration of the agentCs) in dust and the level of dustiness. Also the agent Cs) might be present in cotton dust at higher concentration(s) than in flax dust and its concentration in cotton-seed dust is mostly negligible. It has been suggested that the potentiation effect might be interpreted on basis of : (a) an increase in the number of mast cells formed and/or recruited into the lung, and/or ~ (b) an increase in the capability of the mast cells to form more histamine. 2. Some of the formed histamine is spontaneously released and translocated into blood leading to significantly higher histamine blood levels in all exposed workers than in control subjects. Workers’ exposure to cotton or flax dust will lead to further release of the histamine accumulated in their lungs over the week-end, and; thus, causing the symptoms of byssinosis. However, the released histamine is subjected to metabolism, with consequent decline in its concentration on the second day of the exposure. 3. The rate of hista~ne metabolism is higher in the subjects who are free from respiratory symptoms than in the byssinotic workers, with consequent prolonged histamine accumulation and prolonged appearance of the symptoms of chest tightness and breathlessness in the latter subjects. The variation in the rate of histamine metabolism may be affected by compon­ent(s) in dust, as well as by personal factors in exposed workers. In other words, subjects with hindered histamine metabolism are more I1reactive” to dust exposure and develop­ment of byssinosis. 4. In workers continuously exposed to cotton dust without . week-end interruption the rate histamine formation is nearly equivalent to the rate histamine metabolism with non-considerable histamine accumulation in the lung, and consequent absence of the symptoms of byssinosis.^leng