Longitudinal estimates of pulmonary function decline in grain workers

We conducted a cohort analysis of longitudinal changes in pulmonary function test values in male grain elevator workers in five regions of Canada over a 6-yr period involving three observations. Pulmonary function tests were obtained approximately each 3 yr during an observation interval called a "cycle". The periods of the cycles were 1978-81 (Cycle I), 1981-84 (Cycle II), and 1984-87 (Cycle III), respectively. Data on respiratory symptoms and pulmonary function tests were collected on the same 881 workers in Cycles I and II (mean ages +/- SE: 37.0 +/- 0.48 yr at Cycle I), on the same 1,294 workers in Cycles I, II, and III (34.6 +/- 0.34 yr at Cycle I), and on the same 1,021 workers in Cycles II and III (33.9 +/- 0.38 yr at Cycle II) for a total of 3,196 workers with two or more observations over the 6-yr period. The proportion of current smokers decreased from Cycle I to Cycle III. Autoregression analysis of longitudinal changes in lung function data showed that predictors of FEV1 were height, years in the industry, smoking status, and geographic region. The mean annual losses in FEV1 (FVC) were 28.7 ml (26.4 ml), 38.4 ml (41.9 ml), and 41.7 ml (32.3 ml) for nonsmokers, ex-smokers, and current smokers, respectively. The annual loss of FEV1 (FVC) was 9.2 ml (21.1 ml) for those who were in the grain industry for less than 5 yr and 52.6 ml (60.8 ml) for those who were exposed for 20 yr or more.(ABSTRACT TRUNCATED AT 250 WORDS)

[Food-induced anaphylaxis in latex allergy]

Contact uticaria and anaphylactic reactions to latex-containing rubber products are being recognized with increasing frequency in all kinds of medical disciplines. Recently a number of reports have been published describing anaphylactic reactions to food items in patients with latex allergy. The cases of three patients who developed anaphylactic reactions to both latex and food items are presented, and the importance of the association of latex and cross-reactivity with food items is stressed. The food items that led to anaphylactic reactions were banana and avocado; banana, avocado and buckwheat; and banana, avocado and tomato. The cross-reactivity of latex to buckwheat and tomato has not been reported before.

IgE-binding components of wheat, rye, barley and oats recognized by immunoblotting analysis with sera from adult atopic dermatitis patients

The allergen extracts of wheat, rye, barley and oats flours were characterized by IgE-immunoblotting with serum samples from 40 adult patients; 35 patients with atopic dermatitis, one with rhinitis and four with urticaria. All these patients had been positive when skin-prick testing was carried out with one or more of the four flour extracts or displayed one or more positive cereal RAST results. Four non-atopic sera were used as negative controls. Acidic and neutral protein extracts of wheat, rye, barley and oats flours were processed for the immunoblotting experiments and 35 patients appeared positive in IgE immunoblotting with wheat and rye, 32 with barley and 33 with oats. The IgE immunoblots showed polyspecific binding patterns; wheat exhibited 36 IgE stained bands, rye 35, barley 33 and oats 10. Eighteen of the IgE stained bands could be classified as intermediate allergens for wheat, 23 for rye and 15 for barley. The 66 kDa protein in oats was visualized by 28 out of 33 sera (84%), however, there was evident non-specific binding to this region and thus it may also represent lectin-like binding. The most frequent staining with wheat extract was seen in the 26 kDa protein region (15/35, 43%), with rye in the 40 kDa (16/35, 46%) and with barley in the 26 and 46 kDa protein bands (14/32, 44%). Simultaneous staining with wheat, rye and barley extracts were observed with 16 bands suggesting crossreactivity between these cereals.

Documentation of ill-health effects of occupational exposure to grain dust through sequential, coherent epidemiologic investigation

This review describes the evolution in epidemiologic methods (study design, outcome, and exposure measurements and target population) in relation to knowledge gained concerning the ill-health effects of exposure to grain dust in the workplace over the past three decades. The clinical conditions associated with grain dust exposure are briefly described. Thereafter the study approaches used to investigate grain-related conditions (clinical studies, workforce-based prevalence studies, prevalence studies including unexposed workers, short-term response to exposure, longitudinal studies, supporting evidence from other research arenas, and studies documenting dose-response relationships) are discussed. The objective is to illustrate the strength of sequential, coherent epidemiologic investigation into the ill effects of a particular work environment on human health.

Fish-eaters and farmers: dental pathology in the Arabian Gulf

Twelve skeletal samples, previously published, from the Arabian Gulf have been used to trace differences in diet and subsistence patterns through an analysis of dental pathology. The skeletons date from 3,000 BC to AD 1,500 and cover a variety of geographical locations: off-shore islands, Eastern Arabia, and Oman. The dental conditions analyzed are attrition, caries, calculus, abscessing, and antemortem tooth loss (AMTL). Results indicate four basic patterns of dental disease which, while not mutually exclusive, correspond to four basic subsistence patterns. Marine dependency, represented by the Ras el-Hamra population, is indicated by severe attrition, low caries rates, wear-caused abscessing, and a lack of AMTL. The second group of dental diseases--moderate attrition and calculus, low rates of caries, wear-caused abscessing, and low-moderate rates of AMTL--affects populations subsisting on a mixture of pastoralism or fishing and agriculture (Failaka, Umm an-Nar, Bronze Age Maysar, Bronze Age Shimal, and Iron Age Galilah). Mixed farming populations (Iron Age Maysar and Islamic Bahrain) experienced low-moderate attrition, high rates of caries and calculus, abscessing due to caries, and severe AMTL. The final group of dental diseases affects populations practicing intensive gardening (Bronze and Iron Age Bahrain, and Sites 3 and 5, Ras al-Khaimah). These groups experienced slight attrition, high rates of caries, low rates of calculus deposition, and severe AMTL.

[Sarrazin allergy: a contribution to buckwheat allergy]

Buckwheat allergy is frequent in Asian countries such as Japan because of widespread use of buckwheat in food and bed furniture. In Switzerland such reactions are very rare and mostly due to ingested buckwheat in the form of pizoccheri and buckwheat bread. We describe 6 cases of allergic reactions due to buckwheat comprising urticaria (all pat.), quincke edema (4 pat.) and asthma (5 pat.). 4 patients reacted to ingestion of buckwheat, and 2 patients with occupational exposure were allergic to inhaled buckwheat. Sensitizations were proven in all patients by positive skin tests and specific IgE (RAST). Treatment consisted of strict allergen elimination.

Anaphylaxis caused by banana

An anaphylactic reaction following ingestion of banana occurred in a 32-year-old female cook. The sensitization to banana occurred simultaneously with the development of occupational asthma caused by grain flour. The patient was sensitized to a wide range of airborne and ingestible proteins but not to rubber latex.

Buckwheat-induced anaphylaxis: a case report

Buckwheat (Fagopyrum schulentum) is not taxonomically related to wheat and other cereal grains. Buckwheat flour is used as a wheat substitute in breads, biscuits, pancakes, and crepes. Occupational exposure to buckwheat flour has been associated with rhinitis, conjunctivitis, contact urticaria, and occupational asthma. We present a patient who developed urticaria and hypotension after ingestion of buckwheat crepes. Skin testing by the prick technique revealed 3+ positive reaction to buckwheat with negative reactions to other foods including wheat, egg white, and milk. RAST for anti-buckwheat IgE was strongly positive. Buckwheat ingestion is a potential cause of food-related anaphylaxis. There does not appear to be cross-reactivity between buckwheat and wheat allergy.

Hazardous exposure and lung disease among farm workers

Industrialization of farming, animal raising, and forestry has added new chemical and mechanical hazards that need to be recognized and prevented. Lung disease among farm workers can result from a wide variety of hazardous exposures that include organic dusts, chemicals, and toxic gases. In addition to nonspecific symptoms of mucous membrane irritation, farm workers can develop occupational asthma or bronchitis, organic dust toxic syndrome, hypersensitivity pneumonitis, silo filler's disease (toxic hemorrhagic pulmonary edema), and neuromuscular respiratory failure.

Anaphylactic reactions to a psyllium-containing cereal

Historical data were obtained by questionnaire and telephone survey on 20 of 24 women with reported allergic reactions to a psyllium-containing cereal, Heartwise. Protein fractions from this new cereal, as well as from psyllium mucilloid and a psyllium-containing laxative, Metamucil, were extracted, quantitated, and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Patients' sera were collected, and specific IgE and IgG antibodies to these psyllium antigens were detected by immunoblotting techniques. Of the 20 women evaluated, all but six were nurses. Eighteen (90%) of the women had historical and/or laboratory evidence of atopy. Exposures included ingestion or dispensing of psyllium-containing products. Only three women denied prior exposure to psyllium. Symptoms developed shortly after small amounts of the cereal were ingested and most commonly included moderate to severe wheezing, throat and chest tightness, and urticaria. All the women required medical therapy, 11 (55%) in an emergency room. Specific IgE and IgG antibodies to various psyllium protein fractions were documented in all the subjects. It was concluded that individuals sensitized by occupational exposure to psyllium dust are at high risk for allergic reactions to ingested psyllium-containing products.

Systemic anaphylaxis after ingestion of a psyllium-containing breakfast cereal

Allergic reactions have been described as an occupational hazard among nurses and pharmaceutical workers who handle psyllium-containing laxatives. This study reports the case of a 38-year-old female nurse who ingested a bowl of psyllium-containing Heartwise Cereal (Kelloggs, Battle Creek, MI) and 25 minutes later developed severe systemic anaphylaxis manifested by hypotension, a feeling of constriction in the throat, hoarseness, dyspnea, wheezing, generalized pruritus, urticaria, and vomiting. She was treated with epinephrine, normal saline, diphenhydramine, and methylprednisolone, and recovered completely. Subsequent IgE immunoblot assay was strongly reactive to psyllium. Ingestion of psyllium-containing breakfast foods by sensitized individuals can be associated with life-threatening systemic anaphylaxis.

[Health problems among persons exposed to grain dust]

This review describes health problems in persons primarily exposed to grain dust. The main epidemiological investigations from the nineteen seventies and eighties are reviewed. The commonest complaints were mucus membrane irritation. In the majority of investigations, an excess incidence of chronic bronchitis was encountered and it cannot be disproved that asthma developed in a number of the employees. Influenza-like symptoms compatible with the organic dust syndrome have been described in several investigations from silos but allergic alveolitis has not been described in this branch. The latter condition has been encountered in farm workers working with mouldy grain. With dust concentrations of about the Danish threshold limit value, many health problems still occur. The following prophylactic measures are recommended: Effective drying of corn before storage, effective ventilation and cleaning and covering of dusty working procedures. Epidemiological investigations are proposed in the Danish raw material sector to illustrate health problems related to grain dust. These investigations should be combined with qualitative and quantitative occupational hygienic measurements of dust.

Combined effect of grain farming and smoking on lung function and the prevalence of chronic bronchitis

The combined effect of grain farming and smoking on lung function and the prevalence of chronic bronchitis was examined in 1633 residents 20 to 65 years of age from the town of Humboldt, Saskatchewan. Multiple multivariate analysis indicated that in women grain farming and smoking had a significant synergistic effect on the values of forced expired volume in one second/forced vital capacity (FEV1/FVC), mid-expiratory flow rate (MMFR), flow rate at 50% and 25% of total volume (Vmax50 and Vmax25) after adjustment for covariates including age and height. No other factors were found to change the results. The combined effect of grain farming and smoking on lung function was not statistically significant in men. The data also show that female non-smoking grain farmers had an identical prevalence of chronic bronchitis compared with non-smoking female non-farmers, 2.0% versus 2.1%. But in women with a positive smoking history, the prevalence was 13.2% and 5.9% respectively, giving an adjusted odds ratio in grain farmers compared to non-farmers of 3.55 (95% confidence interval (Cl): 1.06-11.30). It was found that the prevalence of chronic bronchitis increased more rapidly with increasing cigarette consumption in grain farmers than in non-farmers in women. It was estimated that 85%, 72% and 66% of the prevalence of chronic bronchitis was attributed to the joint effects of grain farming and ex-smoking, light smoking (1-19 cigarettes/day) or heavy smoking (20+ cigarettes/day) status, respectively. In contrast to women, the effect of grain farming on the prevalence of chronic bronchitis was similar in men with and without a positive smoking history. Our data suggest that there is a positive interactive effect of grain farming exposure and smoking on lung function and the prevalence of chronic bronchitis in women. The difference in the interaction between men and women requires further study.

Feeding and bedding materials as sources of microbial exposure on dairy farms

Hay, grain, silage, and bedding are the sources of mold dust in agriculture. The aim of the present study was to evaluate the effect of different farming methods on exposure to airborne microbes. The study material comprised 50 silage, 54 hay, 47 grain, and 70 bedding samples taken on 18 farms in the beginning, middle, and end of the indoor feeding season. The modified wind-tunnel technique and six-stage impactors were used to determine the number of mesophilic bacteria, xerophilic fungi, mesophilic fungi, thermotolerant fungi, and thermophilic actinomycetes liberated from each material. Baled hay and straw liberated the largest amounts of microbes. Hay, except when dried in storage, liberated great numbers of fungal spores. The proportion of respirable airborne microbe-bearing particles was greatest in the highest concentrations. Theoretically, choosing the best possible alternative work methods could diminish exposure to microbes to one-tenth of the present level.

Respiratory health status of 3098 Canadian grain workers studied longitudinally

Analyses of data on 3098 male individuals surveyed twice by the Labour Canada Medical Surveillance Program for the Grain Industry are presented. The program collects information on respiratory symptoms, job description, and smoking habits of these workers. In addition, each worker performs pulmonary function tests obtainable through spirometry. Chronic sputum production and chronic wheezing were more prevalent during the latest testing period (rising to 17 percent and 13%, respectively), while the prevalence of chronic cough (16%) and dyspnea (10%) did not change significantly. Eighty-two percent of these workers, in each time cycle, had normal pulmonary function despite an additional 3 years of work exposure. In each cycle, obstructive dysfunction (less than or equal to 12% of workers) was more prevalent than restrictive dysfunction (less than or equal to 5%) or combined obstructive/restrictive dysfunction (less than or equal to 2.4%). It is unknown unknown whether this demonstrated dysfunction is due to previous workplace exposure, as Labour Canada and the Canadian grain industry have cooperated in lowering the grain dust levels found in grain elevators and terminals. In addition, the prevalence of current cigarette smoking has declined. (decreases 5%) among these grain handlers, and there is suggestive evidence that those continuing to smoke have reduced their consumption (mean pack-years changed only from 15.3 to 17.4). Knowledge of environmental dangers and educational programs have contributed to these encouraging results.

Lack of relationship between sorghum consumption, mycotoxin contamination and pellagra in a traditionally sorghum eating population

Traditionally, the disease pellagra has been associated with corn consumption and niacin deficiency, and has presently been recognised as a multiple factor nutritional syndrome. In the recent past, it has been suggested that consumption of mycotoxin contaminated sorghum/corn may be involved in the development of pellagra in a sorghum/corn eating population. The present study relates to the assessment of levels of mycotoxins (aflatoxin B1 and T-2 toxin) in sorghum collected from a traditionally sorghum eating population. Despite 25% fungal contamination in the sorghum samples collected, the levels of mycotoxins were minimal (1.4%) and there was no incidence of pellagra in the survey area. The absence of pellagra in the survey areas may be attributed to the changing dietary pattern.

Causes of schizophrenia

The causes of schizophrenia are discussed in a speculative review in which the disease is considered as a whole body one which is not confined in its pathology or symptomatology to the brain. Both the genetic background and the possible effect of dietary factors are reviewed.

Exposure to grain dust and changes in lung function

Respiratory symptoms and lung function were assessed in 41 seasonal grain handlers and related to duration of employment and level of exposure to grain dust. Ten public works department employees, not exposed to grain dust, were examined during the same period. Respiratory symptoms, forced expired volume in one second (FEV1), and bronchial responsiveness (dose of methacholine provoking a 20% fall in FEV1-PD20) were assessed before starting work and at weekly intervals during a period of employment lasting up to four weeks. Two atopic grainhandlers with pronounced bronchial hyperresponsiveness (PD20 less than 1 mumol) and a history of asthma withdrew from the study within two weeks because they developed severe asthma. Respiratory symptoms were more frequent and more often attributed to work in the grainhandlers than in the non-exposed subjects. In the grainhandlers the FEV1 decreased by a mean (95% confidence intervals) of 321 ml (198-444) (p less than 0.05) and the mean (95% confidence interval) PD20 decreased from 20.6 mumol (10.3-41.2) to 6.0 mumol (2.8-12.5) (p less than 0.05) after one week of work. Over the next three weeks the mean FEV1 returned towards the prestudy values. The mean PD20, however, remained significantly lower than the initial value. The mean FEV1 and PD20 did not change significantly in the non-exposed subjects. The frequency of symptoms and decreases in FEV1 were greater in grainhandlers when working in jobs where total exposure to dust was greater than 20 mg/m3 than when working in jobs where it was less than 10 mg/m3. The results indicate that occupational exposure to grain dust results in respiratory symptoms and changes in lung function, including increased airway responsiveness, within the first week of exposure to grain dust at work. These changes appear to be determined by the degree of dust exposure and suggest a direct effect of grain dust on the lung in these subjects.