Children’s residential exposure to selected allergens and microbial indicators: endotoxins and (1→3)-β-D-glucans

Objectives: The study was aimed at assessment of exposure to endotoxins, (1→3)-β-D-glucans and mite, cockroach, cat, dog allergens present in settled dust in premises of children as agents which may be significantly correlated with the occurrence of allergic symptoms and diseases in children. Materials and Methods: The study covered 50 homes of one- or two-year-old children in Poland. Samples of settled dust were taken from the floor and the child's bed. The levels of (1→3)-β-D-glucans (floor), endotoxins (floor) and allergens of mite, cat, dog and cockroach (floor and bed) were analyzed. Results: Average geometric concentrations (geometric standard deviation) of endotoxins, (1→3)-β-D-glucans, Der p1, Fel d1, Can f1 and Bla g1 in children homes were on the floor 42 166.0 EU/g (3.2), 20 478.4 ng/g (2.38), 93.9 ng/g (6.58), 119.8 ng/g (13.0), 288.9 ng/g (3.4), 0.72 U/g (4.4) and in their beds (only allergens) 597.8 ng/g (14.2), 54.1 ng/g (4.4), 158.6 ng/g (3.1) 0.6 U/g (2.9), respectively. When the floor was covered with the carpet, higher concentrations of endotoxins, (1→3)-β-D-glucans and allergens (each type) were found in the settled dust (p < 0.05). The trend was opposite in case of allergens (except dog) analyzed from bed dust and significantly higher concentrations were found in the rooms with smooth floor (p < 0.05). Conclusions: Among the analyzed factors only the type of floor significantly modified both the level of biological indicators and allergens. The results of this study could be the base for verifying a hypothesis that carpeting may have a protective role against high levels of cockroach, dog and cat allergens

Variation of biocontaminant levels within and between homes--the AIRALLERG study.

Few epidemiological studies report on reliability of exposure measurements even though this significantly influences the results of correlation and regression analysis often used in these studies. Poor reliability of exposure measurement reduces the ability to detect a true association between a certain component and health outcome variables. The aim of this study was to determine the ratio of the within-home and between-home components of variance of a number of biocontaminants measured in house dust in the framework of an international study conducted in the Netherlands, Germany and Sweden (the AIRALLERG study). To this end, duplicate dust samples were collected from children&#39;s beds and from living room floors in over 100 homes. Samples were taken at the same point in time. Variables considered were the dust mass collected in mg/m2 and the concentrations of the house dust mite allergens Der p 1 and Der f 1, cat allergen Fel d 1, endotoxin, (1 --&gt; 3)-beta-D-glucan and extracellular polysaccharides, all per gram of dust and per square meter of sampling surface. An analysis of variance showed that the within-home variance was small compared to the between-home variance for most variables (mostly less than half) with the exception of glucan on mattresses, when expressed in mug/g. Investigation of variation over time is needed for a more complete assessment of the use of these variables in epidemiological analyses of exposure-response relationships

Determinants of house dust endotoxin in three European countries &ndash; the AIRALLERG study.

The comparison of endotoxin levels between study populations and countries is limited as a result of differences in sampling, extraction, and storage procedures. The objective of this study is to assess the levels and determinants of endotoxin in mattress and living room floor dust samples from three European countries, namely, Germany, the Netherlands, and Sweden, using a standardized sampling, storage, and analysis protocol. The mattress and living room floor dust was collected from the homes of 1065 German, Dutch, and Swedish (pre-)school children. All the samples were collected in the cool season and analyzed for endotoxin in a central laboratory. The determinants were assessed by a standardized questionnaire. The endotoxin concentrations in mattress and living room floor dust were found to be the highest in German homes and lowest in the Swedish ones. Differences between the geometric means were small (factor 1.1&ndash;1.7). Most of the associations between endotoxin concentrations and potential determinants were not statistically significant and heterogeneous across countries. However, keeping pets and having more than four persons living in the home were consistently associated with up to 1.7-fold higher endotoxin concentrations in mattress and floor dust. Furthermore, having carpets or rugs, and opening the windows frequently was associated with up to 3.4-fold and 1.3-fold higher endotoxin concentrations in living room floor dust, respectively. The proportion of variance explained by the questionnaire variables was generally low. In conclusion, the data on housing characteristics did not accurately predict the endotoxin concentrations in house dust, and could only partly explain the differences between countries

Levels and determinants of &szlig;(1 - 3)-glucans and fungal extracellular polysaccharides in house dust of (pre-)schoolchildren in three European countries.

Mold growth is believed to be one causative factor underlying the association between dampness in buildings and increased respiratory morbidity. Measurements of &szlig;(1- 3)-glucans and fungal extracellular polysaccharides (EPS) are used as markers of mold exposure in field studies. Little is known about their levels and determinants in homes. Objective To study levels and determinants of &szlig;(1 - 3)-glucan and EPS levels in mattress and living room floor dust in three European countries. Methods Mattress and living room floor dust was collected in the homes of 1065 German, Dutch, and Swedish (pre-)school children. All samples were analyzed for &szlig;(1 - 3)-glucans and EPS in one central laboratory. Determinants were assessed by questionnaire. Results Amounts of dust, EPS and &szlig;(1- 3)-glucan levels differed between countries. Amounts of dust, &szlig;(1- 3)-glucan and EPS levels for mattresses were only weakly correlated with those for living room floors. Floor dust &szlig;(1 - 3)-glucan loads, EPS loads and EPS concentrations were strongly correlated with the amount of dust sampled, which is largely determined by the type of floor that was sampled (carpeted floors had 5&ndash;20 higher amounts of dust). None of the other determinants was consistently and statistically significantly associated with amounts of dust, &szlig;(1 - 3)-glucan and EPS concentrations on floors and mattresses. Conclusion Mattress dust and floor dust are two different measures of exposure to the investigated mold components. Living room floor &szlig;(1- 3)-glucan and EPS loads and EPS concentrations are largely determined by the type of floor sampled. Differences between countries can only partly be explained by the determinants studied

Bacteria and mould components in house dust and children&#39;s allergic sensitisation.

It has been suggested that early childhood exposure to microbial agents decreases the risk of allergies in children. The current authors studied the association between microbial agents in house dust and allergic sensitisation in children aged 2&ndash;4 yrs.Nested case-control studies were performed within ongoing birth cohort studies in Germany, the Netherlands and Sweden and ~180 sensitised and 180 nonsensitised children were selected per country. Levels of bacterial endotoxin, &szlig;(1,3)-glucans and fungal extracellular polysaccharides (EPS) were measured in dust samples from the children&rsquo;s mattresses and the living-room floors.Combined across countries, higher amounts of mattress dust and higher mattress dust loads of endotoxin, &szlig;(1,3)-glucans and EPS were associated with a significantly decreased risk of sensitisation to inhalant allergens. After mutual adjustment, only the protective effect of the amount of mattress dust remained significant (odds ratio (95% confidence interval) 0.57(0.39&ndash;0.84)).Higher amounts of mattress dust may decrease the risk of allergic sensitisation to inhalant allergens. The effect might be partly attributable to endotoxin, &szlig;(1,3)-glucans and extracellular polysaccharides, but could also reflect (additional) protective effects of (microbial) agents other than the ones measured. It is not possible to distinguish with certainty which component relates to the effect, since their levels are highly correlated