Possible Effects Of Xray Films Health And Social Care Essay

Chapter 1

Introduction

The production of radiographic films involves the same methods as photographic film processing. In radiography, x-rays rather than visible light create a latent image on the film surface by reducing silver halide crystals to elemental silver. The image is amplified and stabilized during the developing process using reducing agents such as hydroquinone. The image is fixed by agents which dissolve and remove the unused silver halides. Automated x-ray film processing machines achieve short development times (seconds to minutes) by using elevated temperatures (28-35 °C), by including glutaraldehyde as a hardening agent within the developer solution, and by actively drying the fixed and washed films with heated air [Hewitt, 1993].

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Medical radiographers (MRs) process the x-ray films in a special room called darkroom (DR), this room must contain a special machine with a specific characteristics. The solvents used in DR, to amplify and stabilize the x-ray films, these solvents are developers and fixers solutions, which contain chemicals such as gluteraldehyde, hydroquinone, potassium hydroxide, potassium sulphite, sodium, formaldehyde, thiosulphate, acetic acid, aluminum sulphate, ammonium thiosulphate, and others. Some of these chemicals have shown to cause health problems like asthma (Cullinen et al.,1992; Trigg et al,1992; Chan-Yeung et al, 1993; Gannon et al.,1995; Di Stefano,et al,1999; Smedley et al.,1999).

In addition, other wide variety of symptoms noticed on medical radiographers (MRs) including, nasal discharge, sore throat, sinus problems, sore eyes, headache, fatigue, oral ulcers, tight chest, skin rash, dyspnea, chest pain, and heat arrhythmias (Gordon, 1989; Gannon et al.,1995; Smedley et al.,1999; Wymer et al., 2000).

Other studies investigated the effectiveness of ventilation (local and general) in the darkroom as means to play a great importance to reduce and minimize the hazardous exposures by restoration the air of the radiographic department (Hayes and Fitzgerald, 1994; Helen , 2000; Teschke et al.,2002).

Previous studies titled such research under a general term known as darkroom diseases, which deals with the standard criteria and different ways of processing, practical hygiene , technical maintenance of machine, periodic control and storage of chemical solvents.

The processing chemicals are supplied as concentrates solvents which must be diluted and mixed before use. Whereas it was once common practice for dilution to be done by hand, it is now generally done in automatic mixers, which then provide a direct supply to the X-ray film processor. The processing itself is now also automated so that films are fed into the processor and pass through various stages including immersion in developer, removal of surplus reagent, immersion in fixer, washing in clean water and finally warm air drying.(Bushong, 1993). The processed image emerges with minimum intervention by staff and no direct exposure to chemicals. Some processors are provided with extraction to a waste duct to remove the chemical vapors which could be evolved at the operating temperatures of the processors, typically 28-35°C. (Scobbie et al,1998).

In this study, I try to estimate the possible association between the respiratory problems and the exposure to chemical fumes, in an x-ray film processing room of radiographic department, in the ministry of health in Gaza governorates.

1.1 The purpose of the study:

This study aims to estimate the possible association between the respiratory problems and the exposure to chemical fumes, in an x-ray film processing room of radiographic department, in the ministry of health in Gaza governorates.

1.2 The specific objectives of the study:

1- To determine the clinical symptoms that appear during the working in x-ray room processing of radiographic department.

2- To asses the respiratory status of MRs who are working in both public and private clinics and those who just working in public clinics.

3- To estimate the prevalence of respiratory problems amongst the MRs.

4- To estimate the respiratory status of MRs, by using a matched case-control study.

5- To explore any association between the working years and respiratory status of MRs in an x-ray room processing of radiographic department.

6- To evaluate the process of preparing the chemical fumes in radiographic department.

7- To evaluate the effectiveness of ventilation system (general and local), in the x-ray film processing room (darkroom) and radiographic department.

8- To evaluate the design of x-ray room processing and the preparation process of chemicals used in this processing room.

1.3 Research questions:

1- Is there any signs or symptoms appear in the respiratory system of medical radiographers who exposed to chemical fumes according to the years of working?

3- Is there any significant differences between the medical radiographers who exposed to the chemical fumes, and the control group in the prevalence of respiratory problems?

4- Is there any relationship between the exposure to chemical fumes and appearing of signs and symptoms of respiratory problems?

5- Is the ventilation in the x-ray department plays integral part to minimize the risk of chemical fumes?

6- Is the time of processing play any role to minimize or maximize the prevalence of respiratory problems among the MRs?

7- Is the workload of patients and excess of works to medicals radiographers in any hospital in Gaza governorates, increase the prevalence of respiratory problems? 8- Is the design and positions of darkroom in radiographic department affect on the probability of any health status problems occurrence?

9- Is there any relationship between machine hygiene, used to process the x-ray film and appearance of health problems among the MRs?

10- Is there any control or occupational safety used during the preparation of chemicals in radiographic department?

1.4 Justifications of the study:

Although the hazards of processing chemistry are well documented in the literature and given the importance that the WHO places on safety in the working environment, safety preventative measures are however not operative in darkrooms in may countries (Gordon, 1989; Hewitt, 1993; Teschke et al., 2000; Susan et al., 2004). There is a lack of information of darkroom disease amongst Palestinian MRs. Perhaps, this is because most of the studies were done in develop.

In Palestine, the secondary healthcare is provided by the governmental, non-governmental, United Nation Relief and Works Agency (UNRWA) and private sectors. The Ministry Of Health (MOH) is responsible for a significant portion of the secondary healthcare delivery system (60-70% of general and specialized hospital beds) and more than this proportion in hospital services (about 70% of hospital services). The MOH owns and operates 76 hospitals (22 in Gaza Strip and 54 in the West Bank), furnished with 2,815 beds (1,499 in Gaza Strip and 1,316 in the West Bank). At the end of 2005 there were 654 Primary Health Care (PHC) centers in Palestine; these centers are cared for about 3.7 million people (129 centers in Gaza governorates and 525 centers in West Bank) (Palestine, MOH, 2005).

Gaza governorates suffering from an overcrowded population with shortness space, this fact lead to classify Gaza strip according to the demographic criteria as one of the most popular area in the word (Palestine Bureau Statistics, 2008).

Regarding the previous Gaza governorates hospitals 11 out of 22 hospitals plus 12 out of 129 PHC centers, located in Gaza governorates introduced radiological services, and most of these departments suffering from many problems, one of these important problems is the lack of quality control and occupational safety programs.

In other hand the overload of daily patients obligate the MRs to Strength the times they stay in the department, this leads to increase the risks of exposure to chemical fumes that may enter the body by inhalation and in some cases by direct contact with this chemicals. (Palestine, MOH, 2005).

This problem is exacerbated with defect on the construction and design of radiographic department like the ventilation of department from side, and on the other side MRs neglect the safety rules and programs in the x-ray department, such as the precautions during preparation of the chemicals and processing of x-ray films. Other quality assurance problems are the absence of monitoring and arrangement of priority in the radiographic department to present a good quality of services to patients at the same time minimize as possible as the hazards of radiographic department. So, the emission of the chemical fumes, overloaded patients and lack of control are all lead to produce great problems to the health of MRs and make them under the occupational health hazards which must be in our priority.

The hospitals and medical centers in Gaza governorates are suffering from many problems, some of which are overload working, lack of professionalism, absence of quality control and occupational safety, (Palestine, MOH, 2005).

As an example, Al-Shifa hospital which is considered the biggest hospital in Gaza governorates, the radiographic department includes 43 MRs, each of them stays at least 40 hours weekly half of this time is consumed in the radiographic rooms, and all of them suffer the preparation of chemical fumes from the bad smells and irritability of chemical fumes (marzouk, jan,2008, Direct contact).

Chapter 2

Literature Review

Since the inception of occupational diseases in 1948, the Word Health Organization (WHO) has focused on factors that impact on the health status of working populations’ worldwide. The WHO and collaborative role-players, such as the International Labor Organization (ILO) regularly publish reports on occupational health risks.(NIOSH, 1984).

Investigations by Gordon from 1984-1986, and the British Society of Radiographers in 1991, highlighted the potential threat to the health of radiology workers constantly exposed to x-ray processing chemicals which named this x-ray film processing problems as darkroom disease is a term used to describe unexpected multiple symptoms attributed by medical imaging personnel to their work environment (London, Society of Radiographers ,1991).

An early article by Gordon (1987) also described chest findings in three radiographers and one radiologist, including chest pain with loss of consciousness, arrhythmia, tachycardia and recurring chest infections and lymphoma.

Initial information on the problems arising from an x-ray processing was brought to the attention of radiology workers due to the work of Majorie Gordon a New Zealand radiographer, who was forced to give up her clinical career in 1983 because she became severely 16 sensitized to x-ray processing chemicals. Her main symptoms were tachycardia, hoarseness and extreme fatigue. While visiting Agfa Gevaert plant in Belgium she learned that if the factory workers suffered any signs of respiratory illness they were immediately transferred away from chemical sources. Gordon devoted herself to raising awareness about the safety use of processing chemicals (Gordon, 1989).

In 1987 a study by Ide, found that female darkroom technicians had a greater sickness absence than a matched control group, even though the difference did not reach statistical significance. The author concludes that while occupational hygiene assessments indicated chemical contaminants to be within the limits, further evaluation to determine the cause of sickness absences was recommended.

The British Society of Radiographers (1991) carried out a survey to which 2,804 of their respondents (almost 25%) responded, with 39% of respondents reporting the following symptoms in descending order of frequency, headaches, sore throat/hoarseness, unexpected fatigue, sore eyes, chemical taste, sinus problems/nasal discharge, persistent cold-like symptoms, catarrh, painful joints, mouth ulcers, skin rash and chest pain/breathing difficulties.

Hewitt in his subsequent articles occupational health problems in processing of x-ray photographic films (1993) and reducing the risk in x-ray film processing (1994) points to the increasing reports of respiratory and skin problems since the early 1980s and to common faults observed in various sites, including the positioning of extractor fans being such that fumes released from film processing machines pass into darkroom technicians breathing-zone. Hewitt concluded that the number of cases reported and common features of the conditions described cannot be ignored, and that the consequences of this illness are enormously distressing to the persons concerned, and that the current state of knowledge leaves much more to be learned (Hewitt, 1993).

Smedley and Colleagues (1996) examined the health surveillance of employees exposed to respiratory sensitizing agents, including x-ray departments. In another article published the same year, Smedley et al., (1996) determined the prevalence of symptoms among radiology workers compared with a control group of physiotherapists. They found work-related symptoms suggesting (Headaches, Watery/sore eyes, shortness of breath, lip sores/mouth ulcers, unusual numbness of extremities, unusual heart rhythms, painful joints, irritation of the throat, runny/stuffy nose and nausea).

A study by (Scobbie et al.,1996) investigated the chemical pollutants in an x-ray film processing departments, and revealed that the main airborne contaminants to be sulphur dioxide and acetic acid at concentrations of about 0.1 parts per million (ppm).Glutaraldehyde was not detected either in the ambient air or in the exhaust duct from an automatic film processor. The results of sampling in the processor exhaust duct are shown in Table 1.

Table 1: Demonstrates the concentrations in an exhaust duct of the processing machine:

Concentration (ppm)

Measurement

< 0.002

Glutaraldehyde

< 0.003

Acetaldehyde

< 0.006

Formaldehyde

1.0

Acetic acid (GT)

(a) 0.85 , (b) 0.74

Acetic acid (IC)

< 0.08

Methoxyethanol

< 0.07

Ethoxyethanol

< 0.05

Butoxyethanol

< 0.06

Diethylene glycol

< 0.03

Propylene glycol

0.40

Sulphur dioxide (GT)

(a) 0.76 , (b) 0.77

Sulphur dioxide (IC)

(a) 0.47 , (b) 1.45

Ammonia

24.5 – 45.0

Temperature (oC)

39.0 – 44.0

Relative humidity (%)

In addition, radiographers have reported of a wide variety of symptoms including headaches, sore throat, hoarseness, nasal discharge, sore eyes, fatigue, sinus problems, painful joints, oral ulcers, catarrh, tinnitus, tight chest, skin rash, dyspnea, heart arrhythmias, chest pains, and numbness (Goncalo et al, 1984; Spicer et al., 1986; Gordon, 1987;Smedley et al., 1996; Wymer et al., 2000).

The reagents in the developer and fixer solutions according to various manufacturers’ specifications are listed in the Table 2. (Eastman Kodak, 1993).

Table 2: Reagents in developer and fixer solutions

Developer

Fixer

Acetic acid

Carbonates (potassium, sodium)

Glutaraldehyde (some times as bi-sodium sulphite)

Glycols (diethylene, triethylene)

Hydroquinone

5-nitroindazole

1-phenyl-3-pyramzolidone

Potassium acetate

Potassium hydroxide

Potassium sulphite

Sodium sulphite

Acetic acid

Aluminum chloride

Aluminum sulphate

Ammonium

Thiosulphate

Boric acid

Citric acid

Gluconic acid

Sodium acetate

Sodium bisulphate

Sodium sulphite

Sodium thiosulphite

As a result of previous study National Occupational Health and Safety Commission (NOHSC) considered the chemicals used or produced in radiographic film processing such as acetic acid, formaldehyde, glutaraldehyde, hydroquinone and sulphur dioxide are classified as hazardous substances under the ‘Approved Criteria for Classifying Hazardous Substances’ and are therefore classified as designated hazardous substances.( Bryan, 2001).

Liss and colleagues (2003) investigated the prevalence of asthma and work related respiratory symptoms among MRTs compared with physiotherapists, and to identify work related factors in the darkroom environment that are associated with these outcomes. The result of this study illustrate that the prevalence of new onset asthma (since starting in the profession) was greater among never smoking MRTs than physiotherapists (6.4% v 3.95%), and this differed across gender: it was 30% greater among females but fivefold greater among males. Compared with physiotherapists, the prevalence of reporting three or more respiratory symptoms, two or more work related, and three or more work related respiratory symptoms in the past 12 months was more frequent among MRs, with odds ratios (ORs) (and 95% confidence intervals) adjusted for age, gender, and childhood asthma, of 1.9 (1.5 to 2.3), 3.7 (2.6 to 5.3), and 3.2 (2.0 to 5.0), respectively.

Leinster and colleagues (2007), explored the exposure to glutaraldehyde in cold sterilization and x ray development processes was undertaken in 14 locations at six hospitals in south east England. The results obtained indicated that routine exposures of hospital workers to airborne concentrations of the compound are within the current United Kingdom occupational exposure limit of 0.7 mg m-3. There was the potential for skin contact in many of the activities observed and alternative sterilization and disinfection procedures would have been more appropriate in some situations.

Chapter 3

Methodology

3.1 Study design :

A case control study, to ascertain the possible risk of chemical fumes used in x-ray film processing room on respiratory system of MRs as compared with a control group of physiotherapists (matched to age, sex and smoking habits ).

3.2 Target population :

Medical radiographers working in the radiographic department of governmental hospitals and PHC in Gaza governorates.

3.3 Setting :

This study will be conducted in all radiographic departments, in the ministry of health in Gaza strip, between 1st February 2008 to November 2008.

3.4 Type of sampling :

All medical radiographers who are working in the radiographic department of governmental hospitals and PHC in Gaza governorates, who met eligibility criteria of my study .

Table 5: Distribution of MRs in hospitals of Gaza governorates and number of MRs who met eligibility criteria.

No of MR met eligibility criteria

No of MR

Region

Hospital’s name

6

Gaza North

Beit Hanoun

1

10

Gaza North

Kamal odwan

2

43

Gaza City

Al-Shifa

3

5

Gaza North

Al-Dora

4

2

Gaza City

Specialists Pediatric

5

10

Gaza City

Al-Nassr Pediatric

6

10

Mid-Zone

Shohadae Alaqsa

7

22

Khan Younis

Nasser

8

18

Khan Younis

European

9

6

Rafah

Abu yousef Al-Najar

10

8

Rafah

Al-Hellal Al-Emaraty

11

140

Total

(The Annual report of MOH, 2005).

Table 6: Distribution of MRs in PHC of Gaza governorates and number of MRs who met eligibility criteria.

No of MR met eligibility criteria

No of MR

Region

Name of PHC

1

Gaza North

Beit Hanoun

1

1

Gaza North

Shohadae Jabalia

2

1

Gaza North

Jabalia

3

1

Gaza North

Abu-shbaqe

4

1

Gaza City

Sabha Al-Harazeen

5

2

Gaza City

Al-zytoon

6

1

Gaza City

Al-Shatae

7

2

Mid-Zone

Deir Albalah

8

1

Mid-Zone

Alnussirate

9

2

Khan Younis

Khan Younis

10

1

Rafah

Tel Alsoltan

11

3

Rafah

Rafah

12

17

Gaza governorates

Total

(The Annual report of MOH, 2005).

3.5 Data collection:

The study has two components:

First: Questionnaire Interview

Meeting interview will use for filling the questionnaire, which designated based on the demographic data, age, sex……etc plus the clinical signs and symptoms that may appear on the MR . The questionnaire includes questions related to the MR behaviors and the health impact of exposure to the chemical fumes used in X-ray films processing, specific questions to assess the respiratory system (Venables and colleagues), system of prepare these chemicals , design and quality of dark room and the opinion toward using protective equipment or cloths during preparing these chemicals. Wearing protective cloths, setting and re-entry period in the dark room, smoking, eating, drinking water, chewing gum during the processing time, home structures .

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Second, Follow up :

ٍSpirometry test to assess respiratory system.

1. Spirometry (meaning the measuring of breath) is the most common of the Pulmonary Function Tests (PFTs), measuring lung function, specifically the measurement of the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. Spirometry is an important tool used for generating pneumotachograph to assessing conditions such as asthma, pulmonary fibrosis, and COPD. (David and Rob, 2003)

2. Spirometry testing: The spirometry test is performed using a device called a spirometer, which comes in several different varieties. Most spirometers display the following graphs:

a volume-time curve, showing volume (liters) along the Y-axis and time (seconds) along the X-axis

a flow-volume loop, which graphically depicts the rate of airflow on the Y-axis and the total volume inspired or expired on the X-axis

The most commonly used guidelines for spirometric testing and interpretation are set by the American Thoracic Society (ATS) and the European Respiratory Society (ERS). (Gardner et al.,1997)

3. Procedure:

The basic Forced Vital Capacity (FVC) test varies slightly depending on the equipment used. Generally, the patient is asked to take the deepest breath they can, and then exhale into the sensor as hard as possible, for as long as possible. It is sometimes directly followed by a rapid inhalation (inspiration), in particular when assessing possible upper airway obstruction. Sometimes, the test will be preceded by a period of quiet breathing in and out from the sensor (tidal volume), or the rapid breath in (forced inspiratory part) will come before the forced exhalation. During the test, soft nose clips may be used to prevent air escaping through the nose. Filter mouthpieces may be used to prevent the spread of microorganisms, particularly for inspiratory maneuvers.(David and Rob, 2003)

Table 7: Explanation of common test values in FVC tests.

Description

Name

Abbreviation

This is the total amount of air that can forcibly be blown out after full inspiration, measured in liters.

Forced Vital Capacity

FVC

This is the amount of air that you can forcibly blow out in one second, measured in litres. Along with FVC it is considered one of the primary indicators of lung function.

Forced Expiratory Volume in 1 Sec.

FEV1

This is the ratio of FEV 1 to FVC. In healthy adults this should be approximately 75 – 80%.

FEV 1%

FEV1 / FVC

This is the speed of the air moving out of your lungs at the beginning of the expiration, measured in liters per second.

Peak Expiratory Flow

PEF

This is the average flow (or speed) of air coming out of the lung during the middle portion of the expiration (also sometimes referred to as the MMEF, for maximal mid-expiratory flow).

Forced Expiratory Flow 25-75% or 25-50%

FEF

This is similar to FEF 25%-75% or 25%-50% except the measurement is taken during inspiration.

Forced Inspiratory Flow 25%-75% or 25%-50%

FIF

This measures the length of the expiration in seconds.

Forced Expiratory Time

FET

Slow Vital capacity

SVC

During the respiratory cycle, a specific volume of air is drawn into and then expired out of the lungs. This volume is tidal volume.

Tidal Volume

TV

a measure of the maximum amount of air that can be inhaled and exhaled in one minute, measured in liters/minute.

Maximum Voluntary Ventilation

MVV

Generally speaking, results nearest to 100% predicted are the most normal, and results over 80% are often considered normal. However, review by a doctor is necessary for accurate diagnosis of any individual situation.(American Lung Association, 2001).

3.6 Data analysis:

Descriptive statistics (means for continuous data and counts for categorical) will be used to examine the characteristics of medical radiographic processing facilities determined by the questionnaires survey. To compare continuous data, will use Student tests (t-tests) , and chi-square for categorical data.

Descriptive statistics (arithmetic and geometric means, geometric standard deviations, minima, and maxima) will use to characterize the levels of chemical fumes.

Frequencies, central tendency and dispersion measurements ,cross tabulation and advanced statistical testing like t-test ,ANOVA, correlation and regression will be used to further clarify the relationship between the research variables . All of these statistics will be facilitated by Statistical Package for the Social Sciences (SPSS) version 13.

3.7 Ethical Consideration

To implement this study, I must prepare a proposal and questionnaire that will be sent to the committee of Helsinki to get the ethical allowance of the study. An official letter included the aim of this research to the Ministry of Health in Gaza strip to gain approval to conduct this study at its institutions. A consent form that include (the nature of study, aims, research institutions, participant rights to refuse or withdrawn, plus the guarantee of confidentiality) must cover the questionnaire for better reading , if the agreement occurs the participants must sign the consent form before the data collection occur. Finally, my full address and phone will be sets in the consent form for any clarification about the research and its results.

3.8 Eligibility criteria:

Eligibility criteria for the cases

Any medical radiographer working in the radiographic departments of hospitals and primary health cares in the Ministry of health of Gaza governorates and has the following criteria (at least ten years working service, non smokers, no history of respiratory problems, not exceeded maximum permissible dose (MPD) of radiation dose) (Hewitt et al., 1993;Liss et al., 2003 ;Susan et al., 2004), and between the period of 1st February 2008 to November 2008.

Eligibility criteria for the controls

Any medical laboratory technicians that working in the radiographic departments of hospitals and primary health cares in the Ministry of health of Gaza governorates and has the following criteria (at least ten years working service, not smoking, no history of respiratory problems), and between the period of 1st February 2008 to November 2008.

3.9 Study Limitations

In Gaza strip a punch of limitations faced against the proper performance of this study. First, the objections of MRs to participate in this study, this objection told to the frustration from the ability of these results to change the present situation to the better one. Secondly the Ministry of health sets very difficulty ways to give us the accurate measures and sources or types of the chemical fumes that used in the public radiographic departments. Finally, the instruments and budget needed for medical diagnosis and detection of the chemical fumes in the MRs or in the airborne of the radiographic department.

4-Work Plan schedule

Table 9: showing the work plan time table for the study and the expected date for

each element .

Nov. 2008

Oct. 2008

Sep. 2008

August 2008

July 2008

June 2008

May 2008

April 2008

Mars 2008

Feb. 2008

Activity

Development of proposal

Get Helsinki allowance

Get M.O.H approval

Recruitment of data collector for training

Equipment purchase

Contract a laboratory technician

Research team meeting

Data collection

Data entry in SPSS program

Data analysis

Research writing

Forming the findings writing the conclusion and the recommendations.

5-Refernces:

1. Aaron SD, Vandemheen KL, Naftel SA, Lewis MJ, Rodger MA (2003): Topical tetracaine prior to arterial puncture: a randomized, placebo-controlled clinical trial. Respir Med. 97 (11): 1195-1199.

2. American Lung Association.(2001) Lung diseases-states of the art 2000-2001.New York: American Lung Association, USA.

3. Baillie K, Simpson A.(2006): Altitude oxygen calculator. Apex (Altitude Physiology Expeditions). Retrieved on 08-10.

4. Bryan Ballantyne, Susan L. Jordan. (2001): Toxicological, medical and industrial hygiene aspects of glutaraldehyde with particular reference to its biocidal use in cold sterilization procedures. Journal of Applied Toxicology,21:2-131.

5. Bushong, S. (1993): Radiologic Science For Technologists: physics, biology, and protection, Fifth Edition. Mosby, USA.

6. Chan-Yeung M, McMurren T, Catonio-Begley F, Lam S. (1993): Occupational asthma in a technologist exposed to glutaraldehyde. J. Allergy Clinical Immunology, 91:974-978.

7. Cullinan P, Hayes J, Cannon J, Madan I, Heap D, Newman Taylor AJ. (1992): Occupational asthma in radiographers. Lancet, 340:1477.

8. David P. Johns & Rob Pierce.(2003): The Measurement and Interpretation of Ventilatory Function in Clinical Practice, Second Edition.McGraw-Hill, Australia.

9. Di Stefano F, Siriruttanapruk S, McCoach J.(1999): Glutaraldehyde: an occupational hazard in the hospital setting. Allergy,54:1105-9.

10. Gannon PFG, Bright P, Campbell M,(1995): Occupational asthma due to glutaraldehyde and formaldehyde in endoscopy and x ray departments. Thorax,50:156-9.

11. Gardner RM, Hankinson JL, West BJ. Evaluat