Causes of Chronic Bronchitis in Workers This review shows the literature and research available in the issue of respiratory diseases and the various occupations. The review shows that there is a pressing need to evaluate and conduct research in the known areas like coal, cement, and pesticides, but alarmingly agriculture and other industries have also to be included.

It is not only the factories that are hazardous. There are arguments to show that even farming can cause allergies. Rosenman (2012) in viewing "respiratory hazards that farmers and family members" argues that the grains that can be "contaminated with fungi, bacteria or microbial toxins; pesticides; solvents; gasoline and diesel fuels; and irritant gases such as oxides of nitrogen and ammonia." This may lead to occupational asthma and the allergens in such cases could be grain dust, cow dander, cow urine, egg yolk proteins, alternaria, aspergillus, cladosporium, meal worm, poultry mites, fungi, grain mite, grain weevil and also antibiotics used in feed along with formaldehyde and glutaraldehyde and many types of organic matter. Thus every occupation has its own health hazards. The modern factories and mines have mitigated the hazards with safety practices. (Rosenman, 2012)

There are laws that require adherence to safety practices and in the U.S. The OSHA regulations part: 1910.16, for example, deals with asbestos, tremolite, anthophyllite, and actinolite dust. And the control of exposure of every employee to asbestos, tremolite, anthophyllite, and actinolite dust in every employment and so it has included 'Vinyl chloride.' (United States Department of Labor, 2012) Section 1910.1017 includes 'Acrylonitrile'; Section 1910.1045 'Lead'; Section 1910.1025 includes 'Ethylene oxide' Section 1910.1047 includes 'Methylenedianiline (MDA)'; Section 1910.1050 includes 'Formaldehyde'; Section 1910.1048 includes 'Cadmium'; Section 1910.1027 includes Butadiene (BD), Methylene Chloride, all of which are known disease creators. However the industry wise research on the respiratory system has thrown up results that deal with industries that may be using chemicals not defined in the list. (United States Department of Labor, 2012)

It is true that most factories and workplaces that deal with chemicals and dust entail some of these substances entering the human system through various means. The principal method by which the harmful substances enter human system is through the nasal and oral cavities. Workers tend to inhale dust, fumes and chemicals with which they work and as a result may have contacted diseases, especially of the respiratory system. One of the symptoms that are frequent is chronic asthma, bronchitis, and tracheal infections. There are numerous studies conducted worldwide over this situation and this paper is an attempt at finding the up-to-date findings on this issue. The major industries that are the focal point are the cement industry that is highly polluting, followed by others like the coal, cotton textile, wood, pesticides and other chemical industries. There are many other industries like plastics and construction where materials may cause allergies and respiratory problems.

This paper review the information found so far pertaining to these major industries. Bennett and Bennett (1985) are of the opinion that only recently the occupational airway diseases have received the due attention in the industry, and there is a lack of readily-available data. The interpretation of the data that is available is also scanty and urges that more research be done in the issue. Therefore there has to be further deep research into the issue and more detailed research in various industries conducted.

III. Discussion

The issue of respiratory diseases is important because it leads to greater complications other than asthma or respiratory infections and alterations. For example, Vartiainen; Tuomilehto; Puska, (1996), conducted experiments and epidemiological studies and have proved that there is a link between coronary disease and various infections in different organs, "both viral and bacterial and both acute and chronic." (Vartiainen; Tuomilehto; Puska, 1996) There are even dental infections and infections in the respiratory tract. The chronic respiratory infection leads to coronary disease incidence and mortality and there is a positive association between coronary disease and various infections in different organs especially infections in the respiratory tract. The second importance is that the respiratory diseases may also result in infectious diseases, and this then becomes a...

Other than that the workers are themselves in poor health. Owing to all these factors many researchers have gone into the issue of the allergens for various types of pollutants. However the research thus would cover a vast area and vast number of typology and the spectrum is to be shortened. This can be done by concentrating on obvious symptoms and beginning the research from there. Thus a symptom based analysis would be ideal.
The most important need in the research is to identify the symptoms that are emanating from industrial pollution. There need to be a common variable or symptomatic indicator. The respiratory tract shows common pathology symptoms and the best and therefore one of the key variables that is used to determine and study the issue of respiratory problems with industrial workers is the subtypes of chronic cough, followed by asthma or chronic obstructive pulmonary disease, also found often with chronic cough, and therefore is an indicator of the presence of the pathology causing environment. (Groneberg; Nowak; Wussow; Fischer, 2006) The chronic cough within the workplace shows that there is an occupational contribution to chronic cough and to the symptom cough in general, and as an occupation-related chronic cough is "defined as a disease state that is characterized by the presence of cough for a period longer than three months per year which is caused by an occupational exposure to an airway irritant." (Groneberg; Nowak; Wussow; Fischer, 2006)

The activation of C-fibre receptors shows that there is evidence to link asthma and rhinitis with obstructive respiratory diseases can occur by work-related airflow limitation on account of inhaling or being exposed to allergens, toxins or organic dusts and can cause occupational asthma and COPD. There have also been studies done on animals and animal models on asthma and models of cough for the same substances identify the allergens, irritants such as TDI or other noxious gases such as NO2, SO2 or ozone and the influence of occupational triggers of cough. The animals used were guinea pigs rats and mice and in them a clearly established neurophysiology of the cough reflex has been found. Taking that as a variable, the analysis can now proceed to the various types of industry and how the issue is studied there. (Groneberg; Nowak; Wussow; Fischer, 2006) For that purpose the first one to be chosen is the cement industry because it visibly pollutes and has been the subject of controversy. The cement dust must be causing respiratory problems, more than any other industry.

Cement Dust

There is evidence as per Groneberg, et al. (2006) that exposure to cement dust resulted chronic cough and chronic phlegm among Portland cement workers. Thus occupational Portland cement dust exposure and respiratory health deterioration has a correlation. This was also found to be the case with the Nigerian cement workers and the test for dust-exposed workers and a comparison of rapid declines in FEV1 showed that not only in the cement factories, but also the construction workers both underground and surface construction had chronic cough. On the other hand a negative finding can also be cited. The issue of cement dust in a Portland cement factory and respiratory disease like chronic obstructive lung disease -- COLD using five hundred men was attempted Vestbo; Rasmussen, (1990) and using the data on hospitalization they established that about 7.8% of the total population were admitted to hospital at least once because of respiratory disease and "4.3% had been admitted because of COLD."

The correlation between the duration of exposure to cement dust up to 30 years did not show the result as must have indicated. Therefore Vestbo and Rasmussen (1990) concluded that "long-term exposure to cement dust does not lead to higher morbidity of severe respiratory disease than other types of blue collar work." (Fell; Thomassen; Kristensen; Egeland; Kongerud, 2003) The healthy worker effect and incomplete exposure information have been problems in former studies regarding the association between exposure to Portland cement dust and respiratory effects. The researchers used the estimation of particle exposure for Norwegian cement plant workers using about a hundred workers the research established that "prevalence of chronic obstructive pulmonary disease was 14.3% in the exposed group and 14.0% among the controls. Their findings do not support the hypothesis that cement dust exposure has a negative impact on lung function or gives an increase in respiratory symptoms" (Fell; Thomassen; Kristensen; Egeland; Kongerud, 2003) Another industry with a potential for respiratory diseases is the coal and gold mine sectors. They have also been researched well.

Coal Dust

It is noted here that Groneberg, et al. (2006) reports that the "relation between chronic cough, coal mining and coal miners' pneumoconiosis was examined in 205 miners with simple CWP and 289 without CWP, as a coincidence of pneumoconiosis and chronic cough was suggested before but had never been proofed." In a study on the cellular actions and interactions of key inflammatory cells and target cells in coal…