[Objective assessment of total noise exposure over 24 hours: a cross-sectional study in Bavaria]. / Objektive Bestimmung der 24-Stunden-Gesamtlärmbelastung: eine Querschnittsstudie in Bayern.

INTRODUCTION: Noise can affect well-being and performance of individuals and might be associated with an increased risk of cardiovascular events. To date most epidemiological studies considered exposure from a single source of noise. The EU Environmental Noise Directive (2002/49/EC) requires a summative measurement of ambient noise. This study aimed to capture the participants' exposure to environmental noise by means of personal noise dosimetry. METHODS: Children (n=628, participation=61%, age 8-12 years), adolescents (n=632, participation=58%, age 13-17 years) and adults (n=482, participation=40%, age 18-65 years) were selected randomly from the population registry of 4 Bavarian towns and were invited to participate in a 24-h measurement using noise dosimetry. Noise exposures during day and night were analyzed separately. In addition, predictors of noise exposure were assessed. RESULTS: For daytime noise exposure mean±standard deviation were in children 80.0±5.8 dB(A), in adolescents 76.0±6.2 dB(A), in adults 72.1±6.1 dB(A) (p(ANOVA)<0.001). During the day personal noise exposure was statistically significantly higher for participants from smaller towns than for those living in Munich, while nighttime noise exposure was highest for participants from Munich [44.1±7.2 dB(A)]. CONCLUSION: The summative noise exposure in urban Bavaria is high, in particular among children at daytime. Increased exposure levels in children might be caused by themselves while, e.g., playing. Whether the higher daytime exposure in towns is due to high noise levels commuting between home and work has to be assessed in future studies.

Characterisation of asthma among adults with and without childhood farm contact.

Childhood farm contact is associated with a lower prevalence of sensitisation and allergic rhinitis. Findings have been contradictory for asthma. The aim of the present study was to investigate the differences between farm and nonfarm subjects using objective measurements. A cross-sectional questionnaire study was performed among rural adults aged 18-44 yrs, of which 37% lived on a farm during the first 3 yrs of life and were thus referred to as "farm subjects". Lung function, bronchial hyperresponsiveness (BHR) to methacholine and sensitisation were measured in a random sample. A total of 1,595 subjects were included in the analyses. Among farm subjects, sensitisation against inhalant allergens (odds ratio (OR) 0.7; 95% confidence interval 0.6-0.9), allergic rhinitis (0.5 (0.4-0.8)) and asthma diagnosis (0.7(0.4-1.1)) were less common than among nonfarm subjects. For BHR and lung function, no statistically significant differences were found between the two groups. Stratifying for sensitisation, farm subjects had a lower OR of asthma diagnosis (0.5 (0.3-1.0)) and a nonsignificantly reduced OR of BHR with sensitisation (0.8 (0.5-1.1)). The present study confirmed, using objective measurements, that farm subjects have a lower prevalence of symptoms and asthma diagnosis, while the prevalence of bronchial hyperresponsiveness does not differ.

European dissemination of a web- and case-based learning system for occupational medicine: NetWoRM Europe.

OBJECTIVE: Occupation has a large impact on health in Europe. In order to prevent and recognize occupational diseases, medical students and physicians should know about the potentially causal relationship between profession and diseases as well as the basic legal aspects of occupational medicine (OM). However, the opportunity of bedside teaching, the students' most favoured way of teaching, is limited. METHODS: One possibility to complete and improve traditional training in OM is computer-oriented case-based learning. Using the authoring system "CASUS" (INSTRUCT AG) cases can be created and handled without knowledge in computer sciences. RESULTS: So far, 19 cases have been created and evaluated by students of German universities. Due to the great efforts arising from the creation of such multimedia cases it is desirable and cost-effective to use the existing cases at several medical universities. Therefore, the Net-based Training in Work-Related Medicine (NetWoRM) project shares cases on an international base. In February and April 2005, 13 case-authors from 12 centres were trained in the basics of case creation during a 3 week programme in Munich. The overall evaluation of the participants indicated that this way of teaching case creation is very efficient. Up to now, nine cases were translated into English and five into Spanish. First implementation of the cases in Spain and Finland showed a good acceptance by the students but more evaluation has still to be done. CONCLUSION: Based on these results we conclude that exchange of case-based e-learning in OM is feasible and rewarding on an international base.

[Prevalence of respiratory symptoms and diseases in neighbours of large-scale farming in Northern Germany]. / Atemwegsgesundheit und Allergiestatus bei jungen Erwachsenen in ländlichen Regionen Niedersachsens.

BACKGROUND: Up to now potential health effects of environmental exposure to intensive livestock production facilities have not been thoroughly studied. The aim of the Lower Saxony Lung Study (NiLS) was to assess the prevalence of respiratory symptoms and disease in an area with intensive animal production facilities taking into account environmental exposure to emissions from these large-scale farms. METHODS: All 10 864 inhabitants (age 18 to 44 years) of four towns with a large number of intensive animal production facilities in the area were invited to answer a mail-in questionnaire. Of these, 6416 subjects were randomly selected for the clinical part of the study (specific IgE, lung function measurements, bronchial provocation with methacholine). Overall, 6937 subjects answered the questionnaire (68 %), 60 % took part in the clinical tests. RESULTS: The prevalence of allergic disease in the study population was lower than in urban citizens. Subjects with more than 12 animal houses within 500 m of their home had an increased odds ratio for wheezing without a cold (odds ratio 2.7; 95 % confidence interval 1.4 - 5.4). They also showed a significantly decreased FEV (1) (mean 0.26 l; 0.04 l - 0.48 l) as well as a trend for a lower Tiffeneau-Index. CONCLUSIONS: In result, a large number of intensive animal production facilities might be associated with decreased lung function results in the immediate neighbours. Further studies are necessary to confirm our findings.

Farming exposure in childhood, exposure to markers of infections and the development of atopy in rural subjects.

BACKGROUND: Within the context of the hygiene hypothesis, we aimed to study the potential association between farming-related risk factors and Toxoplasma gondii (T. gondii) as well as Helicobacter pylori (H. pylori) seropositivity. METHODS: The study included questionnaire data and serum samples of 321 young adults living in a rural environment. Serum samples were analysed for specific IgE to a common panel of aeroallergens (SX1) as well as IgG against T. gondii and H. pylori. RESULTS: Regular contact with animal stables before the age of 3 years (odds ratio (OR) (95% confidence interval): 2.0 [1.0; 4.0]) and unpasteurized milk consumption at age 6 years (1.8 [1.0; 3.3]) were the strongest risk factors for T. gondii infection. None of the farming-related factors were significantly associated with H. pylori infection. Current consumption of raw farm milk was not significantly associated with H. pylori infection (2.1 [0.8; 5.3]). Regular contact with animal houses before the age of 7 years was the strongest predictor for atopy (0.49 [0.26-0.96]). The reduction in risk could not be further decreased by any other factor under consideration. After adjustment for animal house contact, the OR for atopy was decreased by raw milk consumption and H. pylori infection in an additive manner. CONCLUSION: Exposure to farming environments in childhood might predict T. gondii seropositivity in rural subjects. Nevertheless, the strongest predictor for atopy in rural subjects seems to be regular contact with farm animals. Whether T. gondii infection is an intermediate factor in the association between farm contact and atopy needs to be confirmed in larger studies.

The "egg-egg" syndrome: occupational respiratory allergy to airborne egg proteins with consecutive ingestive egg allergy in the bakery and confectionery industry.

Allergies to various inhalative allergens are a serious problem in the bakery and confectionery industry. Sensitization to wheat flour and enzymes such as alpha-amylase are a frequent cause of occupational asthma. Airborne egg allergens have been reported as another cause of respiratory allergy. We examined bakery and confectionery workers with respiratory symptoms due to egg aerosols. Skin tests (SPT), scratch tests (ST), nasal provocation tests (NPT) and serological examinations (IgE) were performed. Lung function was assessed by spirometry, and continuous registration of aerosols and particulates as well as gravimetric sampling was done at the workplace. Four bakery and two confectionery workers intensively exposed to airborne egg proteins suffered from conjunctivitis and rhinitis, four also from asthma. Subsequently, three of these four workers reported symptoms after ingestion of food that contained egg. SPT with commercial egg white and egg yolk extracts were negative in four cases. Only two employees had clearly positive SPT to commercial egg allergens and reacted also to wheat flour extracts. Scratch tests with native egg proteins were positive in four employees. Specific IgE to egg white and egg yolk were positive (CAP > or = 2) in three and in four cases, respectively, whereas they were negative in two cases. Elevated levels of specific IgE to lysozyme were detected in four employees. Two workers were sensitized to lysozyme but not to other egg proteins. The clinical relevance of egg sensitization was confirmed by continuous air sampling and by correlating the onset of the respiratory symptoms which were reflected by a significant decline (> or = 30%) of the forced one second capacity (FEV1) in two workers. Sieving of egg white powder and an inadequate spray station for liquid eggs were identified as sources of excessive allergen exposure. Bakery and confectionery workers exposed to airborne egg proteins are at risk of developing occupational asthma and subsequent nutritive egg allergy. To our knowledge, these are the first cases of inhalative egg allergy and subsequent nutritive egg allergy reported in the literature, which we refer to as the "egg-egg syndrome" in analogy to the already known "bird-egg" and "egg-bird" syndromes.

Dust exposure in Munich public transportation: a comprehensive 4-year survey in buses and trams.

OBJECTIVES: Published data obtained from outdoor stationary sampling stations cannot be applied directly to the exposure situation in vehicles. The aim of this study, therefore, was to assess the dust exposure relevant to passengers and drivers in public buses and trams. METHOD: In the years 1993 to 1996, PM10 samples were taken during 201 journeys of typically 4 h duration on 14 routes (nine bus routes, five tramways) which were representative for the overall Munich transportation system with respect to area characteristics and traffic density. The concentrations of the samples were compared with those collected at the same time at sampling stations of the Bavarian State Office for Environmental Protection (OEP). Dust exposure was continuously and synchronously recorded by means of a tyndallometric device. Traffic and passenger density, weather conditions, special events, etc. were noted by our personnel, travelling on every journey. RESULTS: The average PM10 dust concentration for all rides was 155 microg/m3 (single journey max. 686 microg/m3, min. 13 microg/m3). Interior concentrations were 1.7 to 4.0 times above those collected at the static outdoor stations. We found only minor associations between dust concentrations and traffic density or time of day. During several journeys continuous recording disclosed anomalies, dependence on weather conditions and cyclic track characteristics. CONCLUSIONS: Interior PM10 particulate concentrations were comparable to those found elsewhere in truck drivers' cabs and are in the region of German regulative limits established for the general population's long term outdoor exposure. Indoor concentrations were well above the values found at stationary outdoor stations. Additional continuous recording of dust concentrations proved to be helpful in unveiling anomalies and dependencies on external effectors.

Environmental ozone field study on pulmonary and subjective responses of assumed risk groups.

Lung function parameters (measured with a body plethysmograph) and subjective votes on irritations of eyes or airways were taken from subjects belonging to four assumed ozone risk groups and one control group (40 subjects each: senior citizens, juvenile asthmatics, forestry workers, athletes, and clerks). Every subject was examined on 8 days both in the morning and in the afternoon. The intention was to obtain an equal distribution of measuring days with elevated and low ozone concentrations, respectively, for each subject. On average the ozone concentrations reached 0.070 ppm on "ozone days" [maximum concentration 0.112 ppm for clerks (outdoors), 0.100 ppm for senior citizens, 0.091 for juvenile asthmatics, 0.086 ppm for athletes, and 0.077 ppm for forestry workers] and 0.028 ppm on "control days" (minimum 0.001 ppm). The results show no relevant ozone effect for the group with the lowest ventilation rate (senior citizens) and only marginal reductions of respiratory flows and volumes for athletes. Pulmonary decrements of juvenile asthmatics on ozone days were small but larger than those documented in the literature for healthy children. Forestry workers and clerks had significantly higher airway resistances on ozone days, although having been exposed to the lowest ozone concentrations of all groups. Thus, on days with moderately elevated levels of ozone in the environment it is assumed that ozone itself has a minor influence on pulmonary responses compared to that of other constituents of the air in certain locations like in forests or indoors on these days. These could be reaction products of ozone with motor tool exhausts in the case of forestry workers or substances originating from ozone deposition on the surfaces of the offices.

[Lung function and prevalence of irritation of eyes and respiratory airways on days with elevated ozone concentrations]. / Lungenfunktion and Prävalenz von Reizempfindungen an Augen und Atemwegen an Tagen mit erhöhten Ozonkonzentrationen.

In order to evaluate potential health effects on days with elevated ozone concentrations, lung function parameters and subjective votes on irritations of eyes and airways were taken repeatedly from subjects belonging to four assumed ozone risk groups and one control group (at least 40 subjects each) - senior citizens, juvenile asthmatics, forestry workers, athletes and clerks - in comparison of days with elevated (at least 100 micrograms/m3) and low ozone concentrations (at most 80 micrograms/m3). The results show no relevant ozone effects for the groups, "senior citizens" and "athletes", only minor pulmonary effects for "juvenile asthmatics", but significantly higher airway resistances on "ozone days" for "forestry workers" (by 21%) and "clerks" (by 16%). On days with moderately elevated levels of ozone in the environment it is assumed that ozone itself has minor influence on pulmonary responses compared to that of other constituents of the air in certain location like forest or indoors.

Effects of environmental ozone on the lung function of senior citizens.

Measurements with a body plethysmograph of lung function parameters and reports of unusual complaints or irritations were taken from 41 senior citizens in the situations where they usually spend their daytime hours. The subjects belonged to a group commonly assumed to be at risk from ozone. Each subject was examined on 8 days both in the morning and in the afternoon. The object was to obtain for every subject an equal distribution of measuring days between those with elevated ozone concentrations (maximum 0.5 h mean values between 1.00 and 4.00 p.m. of at least 0.050 ppm) and those with low ozone concentrations (maximum 0.5 h mean values between 1.00 and 4.00 p.m. of at most 0.040 ppm). The results showed no relevant ozone related effects on the lung function parameters or the subjective reports of irritations. Thus there was no indication that senior citizens represent a group at particular risk with respect to moderately elevated concentrations of environmental ozone, as occur in central Europe.

[The temporal variation of fine dust concentration in the air in fattening pig housing. Hygienic and occupational medicine aspects]. / Die zeitliche Variation der Feinstaubbelastung der Luft im Mastschweinestall. Tierhygienische und arbeitsmedizinische Aspekte.

The temporal variation of airborne dust concentration (less than or equal to microns) was examined with an instrument operating on the nephelometer principle combined with a specifically adapted data processor in two pig fattening houses at night, at day and during feeding. Activities and factors affecting the dust level were noted. The measurement system allows the uptake and storage of values in the stable. For further processing, the data can be transmitted to a personal computer. In our experience the instrument is very suitable for the registration of airborne dust concentration in animal confinement buildings. Peak concentrations ranging up to 100 mg/m3 in intervals of 10 seconds could be measured. The data of a longer trial were averaged over 1.5 minutes. Animal activity has a great influence on the dust concentration. The highest mean concentration of dust with maximally 2.5 mg/m3 were determined at feeding time and when pigs were disturbed. The concentration of airborne dust particles was obviously lower at night than at day. A defect of the ventilation system, referable to the emission of feed dust, was disclosed by the continuous registration of air dust concentration, in one of the pig fattening houses. During the feeding periods, for a short time of less than 20 seconds, the dust concentration rises to 100 mg/m3 resp. 27 mg/m3 by dry resp. wet feeding. About 30 minutes after feeding the dust concentration was again in the average of 0.67 mg/m3. In conclusion the results were considered under hygienic and medical aspects.

Changes in lung function after working with the shotcrete lining method under compressed air conditions.

Shotcrete techniques under compressed air are increasingly applied in the construction of tunnels. Up to now little is known about the influence of shotcrete dusts on the function of the lung. The lung function of 30 miners working with shotcrete under compressed air (before and after one shift) was measured. They carried personal air samplers to assess the total dust exposure. Long term effects were studied on a second group of 29 individuals exposed to shotcrete dusts and compressed air for two years. A significant increase of airway resistance and a significant decrease of some flow-volume parameters were found after one workshift. These changes partially correlate close to the dust exposure. After two years exposure a significant decrease of mean expiratory flow (MEF)50 and MEF25 was found. These results point to damage in the small airways and emphasise the major role of the lung function test--including the flow-volume manoeuvre for the medical examination of the workers. Additionally, they should carry filter masks.

[Noise-induced hearing loss caused by dental turbines]. / Lärmschwerhörigkeit durch Dentalturbinen.

Sound level measurements and third octave analyses were carried out to estimate the risk of hearing impairment caused by working the turbine drills. Idling noise of two turbines equipped with ball-bearings and air-bearings respectively and the effects of different burs under varying load conditions in particular were examined. Finally, the background sound level in a great consulting room of a dental clinic at medium activity was looked at. Without any exception the sound levels were situated below 85 dB (A). The sound level exceeded 80 dB in only a few third octave bands; this was the case only with the antiquated ball-bearing turbine. Working with turbine drills requires only a fraction of the total treatment duration, resulting in a very low equivalent sound level. As a consequence a hearing impairment risk may be excluded within the reach of this investigation.