Small bakeries--a cross-sectional study of respiratory symptoms, sensitization and dust exposure.

This cross-sectional study investigated the prevalence of respiratory symptoms and sensitization to dust components in 224 individuals in 18 small bakeries in Scotland. Each work practice in the bakeries was characterized by an assessment of dust exposure and assigned to a category with either a direct exposure to flour dust of an indirect exposure to flour dust. We found that work-related respiratory symptoms were significantly associated with specific IgE to wheat flour and amylase but not to exposure category (except for nasal/eye symptoms). However, specific IgE to wheat flour was significantly associated with exposure category. There was a higher prevalence of immunological sensitization, reporting of work-related respiratory symptoms and exposure to dust than in other studies and of the 144 personal dust sample results taken, 21 (14.6%) of the total exceeded 10 mg/m3, the substantial dust concentration as outlined by the COSHH Regulations. Follow-up of those with work-related asthma symptoms (questionnaire response) was inconclusive of the work-relatedness of their symptoms, although it did confirm respiratory morbidity.     

Exposure-response relationships for hexahydrophthalic and methylhexahydrophthalic anhydrides with total plasma protein adducts as biomarkers

OBJECTIVES: This study investigated the exposure-response relationships of hexahydrophthalic anhydride (HHPA) and methylhexahydrophthalic anhydride (MHHPA) and evaluated the applicability of the total plasma protein adducts (TPPA) of these anhydrides as biomarkers of exposure and risk. METHODS: In a cross-sectional study of 139 workers in a plant manufacturing electrical capacitors, the long-term exposure to HHPA and MHHPA was assessed through the quantification of TPPA using gas chromatography-mass spectrometry. Smoking and medical histories were obtained through questionnaires. Work-related symptoms of the eyes and airways were recorded. Specific immunoglobulin (Ig) E (radioallergosorbent test) and IgG (enzyme-linked immunosorbent assay) were determined in serum. RESULTS: The mean level of the TPPA of HHPA was 840 fmol/ml and that of the TPPA of MHHPA was 1700 fmol/ml. There was no correlation between the TPPA of HHPA and the TPPA of MHHPA. Of all the workers, 19% were found to be positive for specific IgE and 17-19% for IgG. Positive associations were observed between HHPA exposure and specific IgE and IgG and between MHHPA exposure and specific IgG. Regarding work-related symptoms, 27% of the workers had symptoms of the nose, 21% had symptoms of the eyes, 11% had symptoms of the lower airways, and 8% had nose bleeding. There were significant exposure-response relationships for symptoms of the eyes and nose for HHPA exposure. CONCLUSIONS: The results show that there is an exposure-response relationship for HHPA both with specific antibodies and with work-related symptoms and down to adduct levels of 40 fmol/ml plasma. In addition, the results elucidate the potential power of TPPA as a relevant index of exposure and risk.     

Occupational exposure to hairdressing chemicals and immunoglobulin E synthesis

OBJECTIVE: This study assessed the effect of exposure to hairdressing chemicals on total and allergen-specific serum immunoglobulin E (IgE) in hairdressers. METHODS: The study was based on a questionnaire sent to 100 hairdressers (91% responding) and a reference group of 95 office workers (84% responding). The questionnaire sought information on allergy, respiratory symptoms during the past year, work conditions (exposure), and smoking habits. The hairdressers were divided into two groups, one of high exposure and another of low exposure. Total serum IgE and allergen-specific IgE towards the most prevalent airborne allergens were analyzed. RESULTS: The serum levels of total IgE were significantly higher among the highly exposed hairdressers than among the office workers. The prevalence of asthma-like respiratory symptoms during the past year was significantly higher among the highly exposed hairdressers than among the office workers. The total serum IgE level was significantly higher among the hairdressers than among the office workers (101 versus 51 IU/ml blood), but this difference disappeared after adjustment for age, atopy, and smoking. A total of 5.5% of the hairdressers versus none of the office workers had specific serum IgE antibodies towards latex. There were no differences in general allergy (Phadiatop) among the hairdressers and office workers. CONCLUSIONS: Serum levels of total IgE were significantly higher among highly exposed hairdressers than among office workers. The relationship could not be completely explained by such covariables as age, smoking, or sensitization to latex allergens.     

Occupational contact urticaria caused by airborne methylhexahydrophthalic anhydride.

Acid anhydrides are low-molecular weight chemicals known to cause respiratory irritancy and allergy. Skin allergy has on rare occasions been reported. A total of 3 subjects with occupational exposure to methylhexahydrophthalic anhydride (MHHPA) and hexahydrophthalic anhydride (HHPA) from an epoxy resin system were studied to evaluate the nature of their reported skin and nose complaints (work-related anamnesis, specific IgE, contact urticaria examinations, and ambient monitoring). Using a Pharmacia CAP system with a HHPA human serum albumin conjugate, specific IgE antibody was detected in serum from 1 (33.3%) out of the 3 workers. One unsensitized worker displayed nasal pain and rhinorrhea only when loading liquid epoxy resins into the pouring-machine (2.2 mg MHHPA/m3 and 1.2 mg HHPA/m3), probably being an irritant reaction. Two workers had work-related symptoms at relatively low levels of exposure (geometric mean 32-103 microg MHHPA/m3 and 18-59 microg HHPA/m3); one complained of only rhinitis, and the other was sensitized against HHPA and displayed both rhinitis and contact urticaria (the face and neck). The worker's skin symptoms were evidently due to airborne contact, since she had not had any skin contact with liquid epoxy resin or mixtures of MHHPA and HHPA. These urticaria symptoms were confirmed by a 20-min closed patch test for MHHPA, but not by that for HHPA. The causative agent was considered to be MHHPA, although the specific IgE determination to MHHPA was not performed.     

Sensitization to green coffee beans and work-related allergic symptoms in coffee workers

Background Occupational respiratory allergy to green coffee beans (GCB) and to castor beans (CB) was studied in 112 workers in a modern coffee manufacturing plant of Trieste (Italy), where the process is completely automatic, the environmental conditions are good and where exposure to CB can be considered absent because since 1970, only new sacks have been used for coffee transportation. Methods All subjects were interviewed by a trained doctor using a questionnaire to investigate allergic symptoms and predisposing factors. Sensitization to GCB and to common allergens (pollens, molds, house dust mites) were evaluated by the skin-prick test. The serum of subjects with a positive skin-prick test to CGB or who had symptoms at work was tested for specific IgE (RAST) for GCB and CB. Lung function was evaluated by a Ponigraph spirometer. Results Sensitization to GCB was found in 25.8% of green coffee workers (31 cases), in 2.7% of roasted coffee workers (37 cases) and in 4.5% of the clerks (44 cases), p < 0.01. The evaluation of IgE specific for CB gave positive results only in 3 of 10 subjects sensitized to GCB. A total of 20% of GCB workers (6 cases) complained of work-related respiratory symptoms (asthma and/or rhinitis) compared with only one subject in the roasted coffee group and one in the control group (p < 0.01). Asthma was reported by 2/31 of the green coffee workers and by 1/44 of roasted coffee workers. Conclusions There was a significant correlation between sensitization to GCB and work related symptoms (p < 0.01), common allergic symptoms (p < 0.05) and atopy by prick test (<0.01). These results point to the need to evaluate atopic status in workers and identify the most susceptible subjects, with the aim of informing them of their at-risk status and monitoring their progress. This makes it possible to diagnose sooner those symptoms possibly indicative of a work-related disease, because even in presence of good environmental conditions and even when symptoms are mild, it is almost always the atopic subjects who are affected. Am. J. Ind. Med. 34:623–627, 1998. © 1998 Wiley-Liss, Inc.     

A clinical and immunological study on 92 workers occupationally exposed to anhydrides

This study aimed at investigating sensitizing and hazardous effects of a new acid anhydride, pyromellitic dianhydride (PMDA), in addition to those of phthalic anhydride, maleic anhydride and trimellitic anhydride, in a group of 92 exposed workers in two German chemical plants. Of the 92 workers, 56 reported work-related complaints with a predominance of phlegm and dyspnoea in those exposed to anhydride dust for less than 1 year. Haemorrhagic rhinitis occurred only after a prolonged exposure of more than 15 years. Specific IgE antibodies to anhydride-HSA conjugates could be detected in 15 exposed subjects, 12 of whom had work-related symptoms. The IgE-positive group had significantly more impaired lung function parameters than the IgE-negative group. The proportion of IgE-positive subjects was highest in the groups with dyspnoea (5/18), cough (6/24) and rhinitis (11/44) whereas only 1 of 11 workers with haemorrhagic rhinitis had such antibodies. A follow-up study of 23 affected workers was performed after 10 months to assess clinical symptoms, lung function and IgE antibody levels. This follow-up study showed the absence of obstructive ventilation patterns in three out of six subjects in addition to cessation of symptoms in most initially affected workers who were no longer exposed. On the other hand, 14 workers under continuous exposure had comparable pathological findings on re-examination. Our results confirm that anhydrides including the lesser known PMDA, behave as respiratory irritants and as immediate-type sensitizers. They predominantly induced reversible symptoms in workers whose exposure stopped after a working period of about 0.7 years. Abnormal lung function parameters normalized in nearly 50% of these subjects.     

新疆吐鲁番地区维吾尔族和汉族成人支气管哮喘相关因素调查分析

目的 探讨新疆吐鲁番地区维吾尔族、汉族成人支气管哮喘(简称哮喘)发病的相关因素,分析可能存在的民族、地区差异.方法 收集吐鲁番地区医院确诊的哮喘患者166例,其中维吾尔族86例(维哮喘组),汉族80例(汉哮喘组)以同期眼科门诊患者为对照,按1:1配对设计.采用问卷调查,血清嗜酸细胞阳离子蛋白(S-ECP)、总IgE(T-IgE)及特异性IgE(S-IgE)检测,进行单因素及多因素条件logistic回归分析.调查结果与我国其他地区的研究资料进行比较.结果 呼吸道感染(OR_维=5.111,95%CI值:1.203～21.710;OR_汉=2.498,95%CI值:1.471～5.069)、家族史(OR_维=3.078,95%CI值:1.812～5.188;OR_汉=2.711,95%CI值:1.010～6.176)、过敏史(OR_维=2.083,95%CI值:1.043～4.162;OR_汉=3.998,95%CI值:1.739～9.198)、气候变化(OR_维=2.218,95%CI值:1.199～3.778;OR_汉=1.733,95%CI值:1.004～2.994)、S-IgE阳性(OR_维=1.592,95%CI值:1.018～2.491;OR_汉=3.858,95%CI值:2.246～8.507)与哮喘的关联有显著性.维哮喘组中呼吸道感染[59.30%(51/86)]、气候变化[36.05%(31/86)]诱发哮喘者高于汉哮喘组[分别为42.50%(34/80)和21.25%(17/80)];汉哮喘组中有过敏史[48.75%(39/80)]、S-IgE阳性者[52.50%(42/80)]高于维哮喘组[分别为32.56%(28/86)和30.23%(26/86)].中、重度哮喘患者血清炎症介质水平测定,S-ECP_维为(7.95±3.98)μg/L,S-ECP_汉为(11.21±4.74)μg/L;T-IgE_维为(72.23±45.92)kU/L,T-IgE_汉为(108.81±64.07)kU/L,均明显高于同民族对照[S-ECP_维为(1.94±1.16)μg/L,S-ECP_汉为(2.07±1.63)μg/L,T-IgE_维为(46.19±32.47)kU/L,T-IgE_汉为(50.97±38.51)kU/L;t值分别为8.96、10.52、2.81、4.97,P值均<0.01].汉族中、重度哮喘患者S-ECP和T-IgE水平均高于维吾尔族(t值3.01、2.68,P值均<0.01).结论 呼吸道感染、家族史、过敏史、气候变化、S-IgE阳性为吐鲁番地区哮喘发病的主要相关因素.中、重度哮喘发作的患者血清中S-ECP和T-IgE水平增高,汉族患者血清S-ECP、T-IgE水平高于维吾尔族.遗传,环境因素对哮喘的发生和发展有影响.     

Byssinosis and serum IgE concentrations in textile workers in an Italian cotton mill

ABSTRACT The relationship between serum concentrations of total IgE and byssinosis and other respiratory symptoms was evaluated in 352 textile workers (90 men, 262 women) at a cotton mill in Friuli-Venezia Giulia, Italy. The subjects were aged from 20 to 61 (mean 44) and the mean duration of employment was 20 years. One hundred and eight subjects (30·7%) were smokers. Only 2% had a positive history of atopy. A standardised questionnaire showed chronic bronchitis in 96 textile workers (27·3%) and byssinosis in 63 (17·9%). The prevalence of respiratory disorders was the same for men and women but was higher in the carding room than in other work areas. Total serum IgE concentrations (RIST, Phadebas) were analysed after log transformation. The geometric mean was 192·7 IU/ml, with no significant difference between the two sexes. This mean concentration of IgE is much higher than that reported internationally for non-atopic subjects, but similar to values found in the Italian population. The IgE concentrations of the workers in the main departments (carding, spinning, and weaving) showed no significant difference. The geometric means were not different in subsamples stratified according to respiratory diseases (cases of pure and cases of mixed forms of chronic bronchitis and byssinosis). A negative result was obtained when IgE concentrations of 289 subjects without byssinosis (¯x = 188·4 IU/ml) and 63 with byssinosis (¯x = 212·6 IU/ml) were compared; there was also no trend when the results were analysed by clinical grade of byssinosis. The same negative pattern occured when the serum IgE concentrations were examined in patients with byssinosis with different grades of chronic change in FEV₁. The results of this study support the hypothesis that there is no relationship between total serum IgE concentrations and byssinosis.     

Occupational asthma due to spruce wood

Workers exposed to a variety of wood dusts are known to experience work-related respiratory symptoms, including occupational asthma. There are, however, few reports of occupational asthma due to spruce wood. We present the case of a 31-year-old sawmill owner with severe asthma caused by exposure to spruce wood dust, who developed asthmatic symptoms after 2 years of working. Investigations included clinical examination, routine laboratory tests, spirometry, chest X-ray, total serum immunoglobulin E (IgE) and specific serum IgEs against various woods and other occupational allergens. Additionally, we monitored the peak expiratory flow rate (PEFR) and symptom score both at work and when off work. Specific serum IgE for spruce wood was detected (7.8 IU/ml). The results of PEFR and workplace symptom-score monitoring, coupled with an elevated eosinophil count in induced sputum, supported the diagnosis of occupational asthma. To our knowledge, this is the first well-documented case of occupational asthma induced by spruce wood dust. A type I immunological mechanism seems to be responsible.     

A cross-sectional survey of 32 workers exposed to hexahydrophthalic and methylhexahydrophthalic anhydrides

The relation between exposure and sensitization or the appearance of symptoms of the eyes and airways was investigated in a cross-sectional study on 32 workers from a plant using epoxy resin with a mixture of hexahydrophthalic anhydride (HHPA) and methylhexahydrophthalic anhydride (MHHPA) as a hardener. The main component in the hardener was HHPA, and the geometric mean concentrations of HHPA in the workplaces were extremely low (<40 microg/m3) in recent years, compared to the Occupational Exposure Limit-Ceiling for phthalic anhydride (2 mg/m3). However, specific IgE antibody to HHPA was detected in serum from 8 (25%) out of the workers: of those, 5 workers experienced symptoms of the eyes and nose during work (group sensitized symptomatic (SS)) and 3 workers did not (group sensitized nonsymptomatic (SN)). The other 24 workers had no signs of sensitization and did not complain of work-related symptoms. Based on occupational history and anamnestic data, it was concluded that one subject in the SS group and all the subjects in the SN group had been sensitized by higher exposures in the past. The symptoms of 4 subjects in the SS group occurred only when carrying out short-time, particular tasks (15-30 min) a few times a day, such as the resin mixing procedures, manual application of the resin, or opening of ovens. High peak exposures were estimated to have occurred during the particular tasks. Our results suggest that short-time peak exposures may have a great impact on the development of specific IgE or work-related symptoms. Therefore, to minimize the risk of sensitization and work-related symptoms, a reduction of exposure during particular tasks with high peak exposures, along with a decrease in mean 8-h time-weighted average exposure, should be achieved.     

Risk factors for sensitisation to methyltetrahydrophthalic anhydride.

OBJECTIVES: To examine an association between specific IgE to methyltetrahydrophthalic anhydride (MTHPA) and exposure time, atopic history, smoking habits, and total IgE concentrations. METHODS: A cross sectional survey was carried out on a population of 148 workers from two condenser plants using epoxy resin with MTHPA, an acid anhydride curing agent known to cause allergy. RESULTS: Using a Pharmacia CAP system with a MTHPA human serum albumin conjugate, specific IgE antibody was detected in serum from 97 (66%) out of the 148 workers exposed to MTHPA. Stepwise multiple linear regression analysis showed a striking relation between log concentrations of specific and total IgE (P < 0.0001). Furthermore, when the workers were divided into two groups according to a cut-off point (100 IU/ml) between low and high total IgE, current smoking was significantly (P = 0.025) associated with specific IgE production only in the group with low total IgE (< 100 IU/ml). CONCLUSIONS: Smoking is the most significant risk factor for raising specific IgE to MTHPA in the group with low total IgE concentrations.     

Diagnostic model for sensitization in workers exposed to occupational high molecular weight allergens

BACKGROUND: Occupational allergy has great impact on workers exposed to high molecular weight (HMW) allergens. The present study is aimed to develop and validate a generic diagnostic model for sensitization to HMW allergens, defined as positive IgE. METHODS: The model was developed in pooled data from Dutch laboratory animal (LA) workers and bakers using logistic regression analysis. Validity was assessed internally by bootstrapping procedure, and externally in British LA workers. RESULTS: The model included working hours/week, work-related symptoms, total IgE, and IgE to common allergen. Significant interactions between the type of work and the predictors resulted in different scores for LA workers and bakers. Internal and external validation showed that the model was satisfactorily calibrated and discriminated between workers at high and low risk of being sensitized. CONCLUSIONS: It is possible to develop a generic model for sensitization to occupational HMW allergens. However, the weighing of predictors differs across specific work environments.     

Lung function and symptoms among cotton workers and dropouts three years after the start of work

A longitudinal study of cotton workers was undertaken to assess the presence of work-related medical effects. A cohort of 110 subjects was examined before starting work and one year later. Measurements of pulmonary function were made before and after the work shift. Airway responsiveness was measured using a methacholine challenge test. A questionnaire was used to determine work-related symptoms. The 60 workers who remained after three years experienced an over-shift drop in FEV1 and an increase in airway responsiveness that did not increase after the first year. The data from the dropout group (n = 50) before work and after one year were compared with those for the active workers. The dropout group had a higher prevalence of symptoms of chest tightness and nasal irritation after one year of work. Atopy was not more common in this group. The results suggest that leaving work was related to symptoms of airways inflammation but not to atopy.     

Airway hyper-responsiveness and the prevalence of work-related symptoms in workers exposed to irritants

The association between exposure to airway irritants and the presence of work-related symptoms and whether this association was modified by airway hyper-responsiveness, smoking, and allergy by history was studied in 668 workers of synthetic fiber plants. A Dutch version of the British Medical Research Council (BMRC) questionnaire with additional questions on allergy and work-related symptoms was used to assess symptoms, and a standardized histamine challenge test of airway hyper-responsiveness (AHR) was employed. Work-related symptoms were defined as having more than usual eye and respiratory symptoms during work. On the basis of job titles and working department, the exposure status of all workers was characterized into seven groups: (1) reference group; (2) white collars; (3) SO₂, HC1, SO₄ ^2-; (4) polyester vapor; (5) oil mist and oil vapor; (6) polyamide and polyester vapor; and (7) multiple exposure. The association between exposure groups and work-related symptom prevalence was estimated by means of multiple logistic regression. The overall prevalence of the work-related symptoms were: cough 9%; phlegm 6%; dyspnea 7%; wheeze 2%; eye symptoms 16%; nasal symptoms 15%. Exposure to airway irritants was significantly associated with work-related symptoms, independent of AHR, smoking, allergy by history, and chronic respiratory symptoms. The association of exposure group with work-related symptoms was stronger for subjects with AHR than for subjects with no AHR. The association with dyspnea and/or wheeze was also stronger for smokers than for nonsmokers and ex-smokers. In contrast, the association between exposure and a higher prevalence of work-related symptoms was stronger in subjects with no history of allergy than in subjects with history of allergy. This is most likely due to the relatively high prevalence of background symptoms in (nonexposed) allergic subjects. It is concluded that exposure to irritants in the working environment might lead to respiratory symptoms, even if exposure levels are relatively low.     

Prevalence of respiratory allergy in a platinum refinery

Summary In a cross-sectional study, 65 workers in the chemical industry with exposure to platinum salts were investigated with regard to the prevalence to allergic respiratory tract diseases. A respriatory questionnaire, a skin-prick test with K₂PtCl₆ and environmental allergens, determination of total IgE, platinum-specific IgE and histamine release in basophilic granulocytes and lung function tests were applied before and after a Monday shift and after a Friday shift. Work-related symptoms of respiratory allergy were present in 23% of all workers, but were significantly more frequent in the most exposed group in the platinum refinery (52.4%). Of all workers, 18.7% had a positive skin-prick test with platinum salt. As compared to the other workers, the workers with work-related symptoms of respiratory allergy had significantly more positive skin-prick tests (64.3%) and a higher total IgE and platinum-specific IgE; they did not, however, show higher histamine release. In the course of the week, a significant fall in lung function, namely in FEV₁ and FEF25, was recorded in the group of workers with work-related symptoms.     

Lung Function and Symptoms among Cotton Workers and Dropouts Three Years after the Start of Work

Abstract

A longitudinal study of cotton workers was undertaken to assess the presence of work-related medical effects. A cohort of 110 subjects was examined before starting work and one year later. Measurements of pulmonary function were made before and after the work shift. Airway responsiveness was measured using a methacholine challenge test. A questionnaire was used to determine work-related symptoms. The 60 workers who remained after three years experienced an over-shift drop in FEV₁ and an increase in airway responsiveness that did not increase after the first year. The data from the dropout group (n = 50) before work and after one year were compared with those for the active workers. The dropout group had a higher prevalence of symptoms of chest tightness and nasal irritation after one year of work. Atopy was not more common in this group. The results suggest that leaving work was related to symptoms of airways inflammation but not to atopy.     

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).     

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).     

Gene expression in nasal lavage from hairdressers exposed to persulphate

Objectives  

Many hairdressers experience work-related symptoms from the airways caused by bleaching powder. This contains persulphates, which could be irritating to the mucous membrane and also may evoke an allergic reaction. However, specific IgE antibodies are difficult to detect. We found earlier that hairdressers with work-related bleaching powder-associated nasal symptoms reacted to persulphate, but that atopics also did and that the mechanism appeared to be similar in the two groups. In this study, we analysed gene expression of cytokines in the nose in order to further investigate the mechanism for work-related bleaching powder-associated nasal symptoms.