Consumer exposure modelling under REACH: Assessing the defaults.

Consumer exposure to chemicals from products and articles is rarely monitored. Since an assessment of consumer exposure has become particularly important under the European REACH Regulation, dedicated modelling approaches with exposure assessment tools are applied. The results of these tools are critically dependent on the default input values embedded in the tools. These inputs were therefore compiled for three lower tier tools (ECETOC TRA (version 3.0), EGRET and REACT)) and benchmarked against a higher tier tool (ConsExpo (version 4.1)). Mostly, conservative input values are used in the lower tier tools. Some cases were identified where the lower tier tools used less conservative values than ConsExpo. However, these deviations only rarely resulted in less conservative exposure estimates compared to ConsExpo, when tested in reference scenarios. This finding is mainly due to the conservatism of (a) the default value for the thickness of the product layer (with complete release of the substance) used for the prediction of dermal exposure and (b) the complete release assumed for volatile substances (i.e. substances with a vapour pressure ⩾10Pa) for inhalation exposure estimates. The examples demonstrate that care must be taken when changing critical defaults in order to retain conservative estimates of consumer exposure to chemicals.

[Associations between bioaerosols coming from livestock facilities and asthmatic symptoms in children]. / Zusammenhang zwischen Bioaerosolen aus Tierhaltungsanlagen und asthmatischen Symptomen bei Kindern.

Although health effects of occupational exposures to livestock emissions are known, potential associations between living in the neighbourhood of intensive livestock facilities and the risk of developing respiratory or allergic diseases are still under discussion. During routine school entry examinations in selected rural districts in Lower Saxony we asked parents about respiratory and allergic symptoms of their 5-6 year old children. A questionnaire with standardised questions of the ISAAC-Studies for respiratory and allergic symptoms and corresponding risk factors was used. Complementarily the children were examined for visible signs of flexural dermatitis and in a subsample the SX1-test was used as an in vitro test for inhalative IgE mediated sensibilisations in capillary blood. Individual exposure to bioaerosols (endotoxin, fungi, bacteria and total dust) coming from livestock facilities was estimated using a Lagrange dispersion model based on the emission rates and locations of the lifestock facilities. A total of 7943 questionnaires (response rate over 85%) were analysed, of which 3867 could be used for the correlation analyses between exposition to endotoxin and asthmatic symptoms. Multivariate logistic regression models were analyzed, considering an atopic disease of the parents as a potential effect modifier and not as a confounder. The prevalence of allergic and asthmatic symptoms is similar to the results of other comparable studies, e. g. "wheezing in the last 12 months" 15.9% for boys and 12.9% for girls. An increase in the prevalence of asthmatic symptoms for higher endotoxin levels was observed only for children of atopic parents. The multivariate controlled odds ratio for one unit logarithm endotoxin concentrations is 1.15, p-value 0.016. Similar effects were observed for other asthma indicators, but not for subjective criteria of the exposition, e. g. the distance to the next large livestock facility guesstimated by parents. Among the overall analysed potential associations between exposition to bioaerosols and asthmatic and allergic symptoms only a few were statistically significant. The discussed association between endotoxin and asthmatic symptoms in predisposed children needs further investigation.

[Human biomonitoring of polychlorinated biphenyls in 130 exposed elementary school children]. / Humanes Biomonitoring auf Polychlorierte Biphenyle bei 130 in einer Grundschule exponierten Personen.

In the classroom air on a primary school polychlorinated biphenyls were present in a wide range extending to 10.220 ng/cbm; in a side room even 19.550 ng/cbm were measured. The school was closed down, a flame retardant paint was detected to be the main source of this contamination. 130 differently exposed persons gave blood specimens for measurement of PCB concentrations. Compared with a comparative reference collective of equal age reported by the analysing laboratory, the PCB blood concentrations of 92 actual pupils were even lower. A comparison with five near-representative child collectives of South Germany did not show any obvious difference. The reference values of the German Human Biomonitoring Commission were exceeded by 4 of 92 pupils for PCB 138, by 6 pupils for PCB 153 and by 6 pupils for PCB 180. In a group of 9 teachers and 1 cleaning person the median values of reference collectives of equal age reported by the analysing laboratory were exceeded by 8 persons for PCB 138, 7 persons for PCB 153 and 8 persons for PCB 180. The 95. Percentiles of these reference collectives and the reference values of the German Human Biomonitoring Commission were not exceeded. In bivariate and multiple regression analyses the data of 92 actual pupils showed positive associations between blood levels of PCB and age as well as nursing period, a negative association between PCB blood concentrations and body-mass index and a weak influence by gender (boys had lower blood concentrations). In addition, the results of multiple regression analyses showed (with the exception of the analyses of PCB 180 without controlling for gender) a significant influence of PCB concentrations in indoor air on PCB blood concentrations. This association could not be detected in bivariate analyses, and in comparison to the mentioned main influence variables it was obviously weaker. But basing on the results of the multiple regression analyses one can calculate an increase of PCB blood concentration by 3% multiplicatively if PCB indoor concentrations increase by 1000 ng/cbm.

[Assessment of health risk due to cadmium contaminated house gardens]. / Zur Abschätzung des gesundheitlichen Risikos kadmiumbelasteter Hausgärten.

An epidemiological survey was conducted on the cadmium intoxication of 132 residents living on former sewage fields. Besides 'global biological monitoring', the relation between the cadmium secretion in urine and the load of cadmium of the kitchen gardens and flower gardens was analysed. There were significant correlations between the cadmium concentration of the residents' garden soil and their daily urine secretion, particularly for older nonsmokers who admitted "at least occasional consumption" of products from their gardens. The value of applying non-parametric correlation coefficients is proven.

[Cryptosporidium infections in AIDS]. / Kryptosporidien-Infektionen bei AIDS.

Investigations for cryptosporidia were carried out on 250 fecal samples from 131 HIV-positive patients between December 1985 and July 1986 with kinyoun carbolfuchsin staining. Cryptosporidial oocysts could be detected in six homosexual men. All of the cryptosporidia excretors had symptoms of enteritis. The clinical course and the prognosis depended on the immunological resistance of the host. Five patients with pronounced immune defect had therapy-resistant chronic diarrhea. In one patient with a slight immune defect, the cryptosporidial infection cured spontaneously. A spacial separation of cryptosporidia excretors and patients with weakened resistance is to be considered in view of the possible severe progress form with low tendency to cure and the still lacking specific chemotherapy.