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Biomedical subjects

C A Pickering

Publications and source records attributed to C A Pickering.

At least 55 records · Page 3Linked to original sources
PubMed1988

Cadmium fume inhalation and emphysema.

Lung function and chest radiographs of 101 men who had worked for 1 or more years manufacturing copper-cadmium alloy were compared with those of a referent group matched for age, sex, and employment status. Cigarette consumption was similar in the two groups. The cadmium workers had an excess of abnormalities of lung function and of radiographic changes consistent with emphysema. Classification of the cadmium workers by exposure categories based on either estimated cumulative cadmium exposure or liver cadmium measured by neutron activation analysis showed that abnormalities of lung function were greatest in those with the highest cumulative cadmium exposure or liver cadmium. The difference in the transfer coefficient (KCO) between cadmium workers and referents increased linearly with increasing cumulative exposure without evidence for a threshold. The estimated mean decrement in KCO for a cadmium worker employed 5 or more years with a cumulative exposure of 2000 yr.microgram.m-3 (exposure to the current UK control limit of 50 micrograms.m-3 for a working lifetime of 40 yr) lies between 0.05 and 0.3 mmol.min-1.kPa-1.l-1 (95% confidence interval). This decrement is consistent with the functional and radiological changes of emphysema observed in this group of workers.

Aged↗
PubMed1988

Recent trends in the prevalence of byssinotic symptoms in the Lancashire textile industry.

A respiratory symptoms questionnaire was completed for 4656 volunteers employed in 31 textile factories engaged in spinning or weaving manmade fibre or cotton of various qualities. Sets of airborne dust and bacteria samples were collected in workzones and personal breathing zones in the workrooms where the volunteers were employed. A total of 182 people indicated experiencing byssinotic symptoms, mainly in opening and carding rooms or in spinning and winding rooms where medium to coarse cotton was being processed. This represents a significant decline in the prevalence of byssinotic symptoms over the years, due possibly to lower concentrations of airborne contaminants, especially of bacteria, as cleaner raw materials are being used. According to a multiple, logistic regression model, the prevalence of byssinotic symptoms was found to be statistically significantly related to years worked in the cotton industry, exposure to dust, quality of cotton used, workroom of employment, ethnic origin, and smoking habits. Symptoms of chronic bronchitis were found to be significantly related to smoking habit and to factors connected with occupation, such as exposure to dust, workroom, and the quality of fibre processed.

Byssinosis↗
PubMed1987

Manchester air disaster.

On 22 August 1985 a fire occurred on a Boeing 737 jet airliner at take off at Manchester Airport. One hundred and thirty seven passengers and crew were on board. Fifty two passengers died on the aircraft, 85 escaped. Most survivors had minor physical injuries, but 15 required admission to hospital because of smoke inhalation and two of these had severe burns. At presentation only one survivor required ventilation but within 12 hours a further five required ventilation. Although initially patients suffering from smoke inhalation may seem relatively well, lung function may deteriorate rapidly in the first 24 hours. Careful organisation and regular practice of procedures to deal with a major accident are essential to be able to respond adequately to such an event.

Accidents, Aviation↗
PubMed1987

Amoebae and humidifier fever.

One hundred and nineteen sera from workers at four different work sites exposed to different contaminated humidifiers were examined by the immunofluorescent antibody (IFA) technique for antibodies to the amoebae Acanthamoeba polyphaga and Naegleria gruberi. Twenty-five of the sera were from workers with humidifier fever (HF) and six from workers with work related asthma (WRA) shown to be due to the contaminated humidifiers. A positive IFA test was found to correlate precipitin reaction to humidifier antigen, but did not correlate with smoking habit, work related symptoms (detected by standard questionnaire) or with HF or WRA. Amoebae were identified in all humidifiers studied.

Amoeba↗
PubMed1987

Clinical and immunological investigations of respiratory disease in workers using reactive dyes.

A questionnaire survey of over 400 workers handling reactive dyes showed that over 15% had work related respiratory or nasal symptoms. Forty nine employees with symptoms were referred to chest clinics for detailed assessment. It was considered that in 19 the symptoms could be attributed to an irritant response to a variety of chemicals, including hydrochloric acid vapour, sulphur dioxide, and reactive dyes. Symptoms in 24 were attributed to an allergic reaction to a specific agent; in most (21) to one or more reactive dyes. Two patterns of allergic lower respiratory symptoms were identified; an immediate response of short duration and a longer lasting response, usually of several hours, sometimes accompanied by nocturnal asthma. A radioallergosorbent test (RAST) screen containing the most commonly used reactive dyes was used to detect specific IgE. Allergic symptoms to reactive dyes were strongly associated with specific IgE (17/21 employees) and atopy (18/21). Irritant symptoms were also associated with atopy (13/19) but only weakly associated with specific IgE (7/19).

Coloring Agents↗
PubMed1986

Physiological evidence that emphysema is not a feature of byssinosis.

A group of women with byssinosis of grades 2 and 3 were seen consecutively over three years in an occupational outpatient clinic. Detailed lung function tests were performed and the results for smokers and non-smokers compared. One hundred and fifty three patients were seen and 50 of these were life time non-smokers, 35 smoked one to nine cigarettes a day, and 68 smoked 10 or more cigarettes a day. After correction for age the mean FEV1 was found to be significantly lower (p less than 0.01) in heavy smokers than in non-smokers. In a subgroup of 89 subjects who were able to perform the carbon monoxide gas transfer test significantly lower values were obtained for the carbon monoxide transfer factor (TLCO), (p less than 0.001), TLCO % predicted (p less than 0.001), and the transfer coefficient (KCO) (p less than 0.001) in the heavy smokers than in the non-smokers, despite the fact that the non-smokers had worked longer in the cotton mills (p less than 0.02). The mean TLCO was significantly lower than predicted in the heavy smokers (p less than 0.001) but not in the non-smokers. A significant negative correlation was found between the number of cigarettes smoked per day and the TLCO (p less than 0.01), TLCO % predicted (p less than 0.001), and KCO (p = 0.005), but not with the number of years spent in the carding area. These results provide evidence supporting recent pathological observations that emphysema is probably due to concomitant cigarette smoking and is not itself a feature of byssinosis.

Aged↗
PubMed1985

Comparison of health problems related to work and environmental measurements in two office buildings with different ventilation systems.

A cross sectional survey investigating "building sickness" was carried out in two buildings with similar populations of office workers but differing ventilation systems, one being fully air conditioned with humidification and the other naturally ventilated. The prevalence of symptoms related to work was assessed by a questionnaire administered by a doctor. A stratified, randomly selected sample of workers was seen (84% response). Building sickness includes several distinct syndromes related to work, most of which were significantly more common in the air conditioned building than the naturally ventilated building--namely, rhinitis (28% v 5%), nasal blockage and dry throat (35% v 9%), lethargy (36% v 13%), and headache (31% v 15%). The prevalence of work related asthma and humidifier fever was low and did not differ significantly between the two buildings. An environmental assessment of the offices was performed to attempt to identify possible factors responsible for the differences in the prevalence of disease. Globe temperature, dry bulb temperature, relative humidity, moisture content, air velocity, positive and negative ions, and carbon monoxide, ozone, and formaldehyde concentrations were all measured. None of these factors differed between the buildings, suggesting that building sickness is caused by other factors.

Air Conditioning↗
PubMed1985

Factors affecting the development of precipitating antibodies in workers exposed to contaminated humidifiers.

A total of 601 sera from groups of workers exposed to heavily and moderately contaminated humidifiers respectively were examined by the double diffusion test for precipitating antibodies to humidifier extracts. Clinical information was obtained using a standardized questionnaire. Skin-prick tests to control, to three common inhalant antigens and to an extract from the humidifier were performed in 103 subjects exposed to a heavily contaminated humidifier. In this environment a strong inverse relationship between current smoking and precipitins was detected (P less than 0.001). Pack years smoked had no bearing on precipitin level. In the larger study there was a clear dose response effect of smoking on precipitins. The effect of smoking appeared to reverse within 3 years. Duration of exposure also had a major effect on the development of precipitins with a clear 'dose response' again being seen in the larger study. These relationships did not apply in the groups exposed to moderately contaminated humidifiers. Levels of airborne antigen were measured using a competitive ELISA inhibition assay and were found to be much lower in sites with moderately contaminated humidifiers than at sites with heavily contaminated humidifiers. Our results suggest that the airborne antigen level is crucial in determining the pattern and strength of precipitin response in smokers and non-smokers exposed to contaminated humidifiers.

Air Pollutants, Occupational↗
PubMed1985

Occupational asthma in a steel coating plant.

An outbreak of occupational asthma, of unknown cause and extent, was detected in a steel coating plant. In 1979 a cross-sectional study which defined occupational asthma in terms of respiratory symptoms detected 21 people with suggestive symptoms among the 221 studied. They all worked in the coating shop, but the plastic coatings used at the plant contained many potential sensitising agents that might have caused the asthma. All 21 developed their symptoms after 1971, and it was found that in this year a supplier had modified a coating allowing, at the temperatures used in the process, toluene di-isocyanate to be liberated. Two of the symptomatic subjects were tested by inhalation of the isocyanate and showed asthmatic reactions and other subjects were found to have asthma related to periods spent at work by records of peak expiratory flow rate. Over half the 21 had a symptom free latent period after first exposure of three years or less, a pattern not seen in other subjects with respiratory symptoms. After the isocyanate had been removed from the process 17 of these subjects became asymptomatic or improved, a greater proportion than in other subjects with respiratory symptoms.

Adult↗
PubMed1985

Occupational asthma in a factory with a contaminated humidifier.

Thirty five printers who had work related wheeze, chest tightness, or breathlessness kept two hourly records of their peak expiratory flow for at least two weeks. They all worked in a factory supplied by air from contaminated humidifiers. The peak flow records showed consistent work related deterioration in 15 workers, nine of whom had a diurnal variation in peak flow exceeding 20%. Ten workers kept further records after the humidifiers had been cleaned, other work practices remaining unchanged. There was substantial improvement in all 10 workers, implying that material from the contaminated humidifier was the cause of the work related changes in peak flow. The patterns of work related changes in peak flow fell into four groups: falls maximal on the first work day, falls maximal midweek, falls equivalent each work day, and falls progressive throughout the working week. Three quarters of this last group had immediate prick test responses to humidifier antigen, which were negative in all the others with work related changes in peak flow. This suggests that the progressive daily deterioration pattern alone is due to an IgE mediated response to humidifier antigens. A large range of microorganisms was identified in the humidifiers. No single microorganism appeared to be the antigen responsible for the precipitating antibody seen in 75% of the study population.

Air Conditioning↗
PubMed1984

The sick building syndrome: prevalence studies.

Random samples or the entire workforce in nine offices in which similar clerical work was being performed were studied using a doctor administered questionnaire that inquired into symptoms that have been linked with the "sick building syndrome." Five of the offices were fully air conditioned, one had recirculation of air and mechanical ventilation, and three were naturally ventilated. Workers in three air conditioned and three naturally ventilated buildings were interviewed blind. Seven of the buildings were studied at our request in the absence of any known problem. Comparison of prevalences of symptoms between the naturally ventilated and the other buildings showed a repeated pattern of nasal, eye, and mucous membrane symptoms with lethargy, dry skin, and headaches. There were highly significant excesses of these six symptoms in the air conditioned buildings when compared by chi 2 tests with the naturally ventilated buildings. It is suggested that these six symptoms represent the sick building syndrome and that the size of the problem is probably greater than is currently recognised. Possible causes are discussed.

Air Conditioning↗