No increase in the prevalence of asthma, allergies, and atopic sensitisation among children in Germany: 1992-2001

BACKGROUND

From 1970 to 1990 increasing rates of asthma and allergic sensitisation were observed in several countries. The aim of this study was to investigate time trends in the prevalence of asthma and allergic sensitisation among school children in Germany between 1992 and 2001.

METHODS

Parental reports of asthma, hay fever, and wheezing and measurements of specific serum IgE antibodies were investigated in six serial cross sectional surveys of 9-11 year old school children in three study areas in south west Germany.

RESULTS

A total of 6762 school children of mean age 10 years (mean participation rate 77.9%) took part in the investigation in the three study areas. Over the 9 year study period no increase in the prevalence of current wheezing and asthma was observed. In addition, the prevalence of atopic sensitisation remained unchanged during the observation period.

CONCLUSIONS

These data, using parental reports and objective measures of allergy, suggest that there has been no further increase in the prevalence of asthma and atopy since 1992. The epidemic may thus have reached a plateau.

Humanbiomonitoring-Untersuchungen von Organohalogenverbindungen - PCB, DDE; HCB, β- und γ-HCH, PCDD/PCDF, koplanaren PCB sowie polybromierten Biphenylethern

Although PCB and PCB-containing materials are not processed for a long time, PCB is under discussion again and again caused by the pollution of indoor environments. To objectify the discussion, the dates of the PCB-biomonitoring, the organochlorine-compounds (DDE, HCB, beta-/gamma -HCH, PCDD/PCDF) and the polybrominated biphenyl ethers concerning the investigations within the project "Sentinel Health Departments" in Baden-Wurttemberg are represented. Additionally results from children from Kazakhstan (Aral-Sea area) and from teachers which are working in PCB polluted schools as well as from a long term investigated test person are reported. Blood concentrations of the following compounds decreased from 1996/97 to 2002/03: the sum of the concentration of PCB 138,153 and 180 decreased from 0.46 microg/L to 0.20 microg/L, DDE from 0.32 microg/L to 0.17 microg/, HCB from 0.20 microg/L to 0.08 microg/L, beta-HCH below the level of detection, I-TEQ NATO to 4.8 pg/g blood fat, TEQ WHO (without PCB) to 5.5 pg/g blood fat, PCB 126 to 18,8,pg/g blood fat and PCB 169 to 12.8 pg/g blood fat. The influence of breast feeding and the gender on the level of the pollution is conspicious. No local correlations were found in Baden-Wurttemberg, but they were found in comparison with the results of Kazakhstan (Aral-Sea area). The difficulty to produce time series while the analyzing pollutants are more and more decreasing, as well as the change of the calculation base of the summation of parameters like I-TEQ NATO to TEQ WHO are discussed.

[Exposition and sensitisation to indoor allergens, house dust mite allergen and cat allergens]

The study examined the exposure to biological indoor air agents and their possible role for allergies and respiratory tract illnesses of children. It was conducted as a case control study (atopic vs non-atopic children) at the four surveillance public health departments in Baden-Württemberg in the winter season 1999/2000 and included 379 children of the fourth class. The concentrations of the house dust mite antigens Der F1, Der p1, and Der Gr2 as well as cat allergen Fel d1 were determined in the children's bedrooms on the ground and in the mattress. Specific IgE-antibodies against allergens from house dust, mites and cat were determined in the serum of the children. For mite allergens the following medians ( micro g/g) were estimated in floor dust: Der p1 = 0.6, Der f1 = 2.3, Gr2 = 0.1; in mattresses: Der p1 = 1.2, Der f1 = 3.4, Gr2 = 0.3. The median of Fel d1 in floor dust was 0.2 microg/g, in mattresses 0.1 microg/g. Sensitisation to dust mite allergen was found to be more prevalent than sensitisation to cat. The distribution of sensitisation among the cases and controls is different. Among the cases, more subjects were sensitised to dust mites (32.9 %) and cat (13.1 %). Among the controls, 17.1 % were sensitised to dust mites and 4.1 % to cat. The results showed no direct association between the prevalence of allergies or respiratory tract illnesses and the indoor concentrations of the allergens. Possible reasons for these findings are discussed.

[10 years of observation by public health offices in Baden-Württemberg--assessment of human biomonitoring for mercury due to dental amalgam fillings and other sources]

Since 1992, in Baden-Württemberg, ten-year old children have been surveyed in the project "Sentinel Health Departments" to study their exposure to environmental pollutants and possible health effects. In the four study areas 1200 children have been investigated every year initially, since 1996 every second year. The data for mercury in body fluids are reported here. The decrease in the body burden of mercury as a result of the declining usage of dental amalgam fillings, was been verified. In 1992/93, of all the children who had been surveyed, the 95 percentile for the body burden of mercury was 3.1 microg/l and in 2000/01 1.35 microg/l. Also to be discussed is the reason why mercury-based cosmetic ointments seriously exceed the HBM-II-intervention-value. Because of using these ointments, concentrations of mercury in urine up to 1400 microg/l were found. A study within the project "Sentinel Health Departments" compared the concentrations of mercury in the urine of adults with those in blood and salvia. The results support the opinion that mercury in urine is appropriate for estimating the mercury uptake from dental amalgam fillings. It can be assumed that these results reflect the situation in the entire Federal Republic of Germany. The ten years' experience confirms that the concept of the "Sentinel Health Departments" is excellently suited to obtain data relevant for environmental health of children. Environmental health protection and the essential gathering of data for future health observation in Baden-Württemberg.

[Serum selenium levels in school children: results and health assessment]

BACKGROUND

In Germany, where geogenic selenium concentrations are low, only few data on selenium status in children are available. Aim of the study was to investigate serum selenium concentrations of children in a population-based sample and to additionally investigate spatial and temporal differences.

METHOD

In three consecutive cross sectional studies the selenium concentration in serum was determined in 1,918 children (mean age 10.3 years) from four study areas. Potential factors of influence were assessed by questionnaires filled in by parents and physicians, respectively. Selenium determination was done by hydride atomic absorption spectrometry after microwave digestion.

RESULTS

Mean selenium concentrations for the subcollectives ranged from 54.5 +/- 10.5 micro g/l to 71.9 +/- 15.1 micro g/l. The minimum observed was 14 micro g/l, the maximum 216 micro g/l. Turkish children had lower selenium concentrations than German children and children of other nationality, respectively. Controlling for sex and year of investigation German children from Stuttgart had significantly lower selenium concentrations than children from Aulendorf/Bad Waldsee. In the same regression model for the period from 1995/96 to 1998/99 a decreasing trend was found to be significant. However, the regression model only explains a very small part of variance.

CONCLUSIONS

The selenium concentrations determined in this study are in the range also found in other studies in children from Germany. They are far below the toxicologically relevant range, which starts at about 600 micro g/l. The 5 th percentile in nearly all subcollectives was below the threshold limit of the lower tolerable selenium concentration of 45 micro g/l. For children from south Germany deficiency of selenium is therefore more to be suspected than a burden relevant to health. Selenium supplementation should however be considered thoroughly. Balanced nutrition is also a main factor for an optimum selenial supply.

[Assessment of mould pollution in residences in southwest Germany]

Elevated levels of moulds in homes may represent a risk for development of allergies and respiratory diseases. Little is known about the levels of these biogenic contaminants in homes in South-West Germany. This paper presents the results of a study which was performed between November 1997 and May 1998 in the four Sentinel Health Departments in Baden-Württemberg (Stuttgart, Mannheim, Kehl and Aulendorf/Bad Waldsee). It included 377 households in which children of 10 years of age resided. Moulds were determined in indoor air, outdoor air, household dust from floors and mattresses. Specific home characteristics were assessed by questionnaire. The median value of the number of colony forming units (CFU) in indoor air was 135 CFU/m3 (range 5-17,000) and in outdoor air 145 CFU/m3 (range 15-2,900). The median value of CFU/g dust, collected from the floors, was 15,000 (range 0-700,000) and collected from mattresses was 28,000 (range 1,500-1,350,000). The data suggest that an indoor-outdoor difference exceeding the value of 500 CFU/m3 indicates an elevated mould concentration in indoor air compared to background. This value can be discussed as a temporary reference value for South-West Germany in the winter season. However, a health assessment can not be derived from this value.

PCB-blood levels in teachers, working in PCB-contaminated schools

In order to get more information about potential health hazards due to indoor air PCBs the present study investigated the PCB indoor concentration in schools as well as the blood levels of 6 PCB-indicator congeners in teachers from these schools. 151 teachers (78 male and 73 female; mean age 48 years) from 3 contaminated and 2 control schools participated in the study. Maximal indoor air values for total PCBs (6 PCB-indicator congeners times 5) in schools ranged from 1587 to 10655 ng/m3. Blood analyses indicated an increase in mean PCB 28 level from 0.036 (control group) to 0.098 microg/l in teachers from a school with heavy contamination of low chlorinated PCB. But there was no significant increase of PCB 138, 153 and 180 in blood above the normal background concentrations in any of the contaminated schools (mean values of all groups: PCB 138 = 0.66, 153 = 0.95, 180 = 0.70 microg/l blood). The results of blood analyses and additional toxicokinetic calculations suggested that inhalative PCB-uptake in the most contaminated schools caused a minor increase above mean background-PCB concentrations in blood. In conclusion, despite high PCB indoor air levels in schools, there was only a moderate increase in blood concentrations of teachers, mainly due to congeners with low chlorination (PCB 28 to PCB 101).

First data on background levels of non-ortho and mono-ortho PCBs in blood of residents from southern Germany

Blood-fat concentrations of polychlorinated biphenyls (PCB) congeners: no. 105, 118, 156 (mono-ortho-substituted) and no. 77, 126, 169 (non-ortho-substituted) and PCB congeners no. 28, 52, 101, 138, 153 and 180 were measured. The investigations were carried out in pooled samples from children and in individual samples from adults. Additionally polychloro-p-dibenzodioxins and -furans (PCDD/PCDF) were investigated.

[Sentinel public health offices--a new approach to determining public health relevant data by the public health service]

The discipline of environment-related health protection lacks continuously recorded data. Therefore, a three-year pilot project "Sentinel Public Health Offices" was initiated by the Ministry of Labour, Health and Social Welfare of Baden-Württemberg in 1992. Selected public health offices were instructed to conduct a series of three cross-sectional surveys of biological and effect monitoring among children attending the fourth grade of primary schools. The surveys were coordinated by the Provincial Public Health Office. During the pilot project the system of " Sentinel Public Health Offices" has proved successful not only in the continuous recording of data relevant to health. Its continuation as a permanent institution is contemplated.