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UBC Theses and Dissertations

Indoor mould, dust mite and endotoxin exposure in Aboriginal housing in British Columbia : an assessment in the Heiltsuk first nation community Osterberg, Patricia Margaret


Concerned with mould exposure in reserve housing, the Heiltsuk First Nation participated in a CIHR-funded research project to assess residential indoor air quality. Biological particles including moulds, dust mites and endotoxins, and questionnaires based on health status and home environment for 43 homes were studied to understand exposure risks (determinants of exposure). The Heiltsuk were partners in this research project. They consented to the initiative and implementation of the project, shared their knowledge and were the trainers and the trainees — examples of selfdetermination. Odds Ratios (α = 0.05) were applied to air and dust samples and compared with the questionnaires. The geometric mean (GM) for indoor airborne mould concentration was 509 CFU/m³ (range 7 — 18,582 CFU/m³). In bedroom carpet samples, dust mite protein, DerPi, levels ranged 0.1 — 150 µg/g (GM 15 µg/g). In other rooms, levels ranged 0.1 —55 µg/g (GM 1.3 µg/g). DerP2 levels ranged 0.1 — 180 pg/g dust (GM 14.7 pg/g) for bedroom samples and 0.1 — 110 µg/g (GM 2.1 µg/g) in other rooms. An association was found between bedroom dust samples and mite sensitization levels (>2.0 µg/g) for DerP1 (OR 5.5; 95% Cl 1.194—25.51 7; P = 0.029) and DerP2 (OR 10.1; CI 0.922 — 111.247; P = 0.058). An association was also found between levels of mould concentrations and reported respiratory treatment (OR 8.2; Cl 1.977 — 34.431; p = 0.04) but not with levels of dust mite concentrations. Indoor to outdoor fungal ratios exceeding unity were associated with reported asthma symptoms (OR 4.0; Cl 1.040 — 15.381; P = 0.44), allergy symptoms (OR 4.5; CI 1.138 — 17.965; p = 0.03) and carpet age (OR 4.5; Cl 1.252 — 16.171; P = 0.021). Thus dust mite allergens in the bedrooms and the levels of mould concentration in the homes, especially when amplified, indicate a health risk. A significant determinant of exposure to mould was carpet age, which was identified both by analysis of samples and by communicating with the Heiltsuk. These data will contribute to population and public health promotion and baseline data. Heiltsuk self-determination catalyzed community engagement in education, remediation, and health promotion programs.

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