Relationships between House Characteristics and Exposures to Metal(loid)s and Synthetic Organic Contaminants Evaluated Using Settled Indoor Dust
- DOI
- Language of the publication
- English
- Date
- 2022-09-19
- Type
- Article
- Author(s)
- Rasmussen, Pat E.
- Kubwabo, Cariton
- Gardner, David H.
- Levesque, Christine
- Beauchemin, Suzanne
- Publisher
- MDPI
Abstract
This study investigates associations between house characteristics and chemical contaminants in house dust, collected under the nationally representative Canadian House Dust Study (2007–2010). Vacuum samples (<80 µm fraction) were analysed for over 200 synthetic organic compounds and metal(loid)s. Spearman rank correlations between contaminant concentrations in dust and presence of children and pets, types of flooring, heating styles and other characteristics suggested a number of indoor sources, pointing to future research directions. Numerous synthetic organics were significantly associated with reported use of room deodorizers and with the presence of cats in the home. Hardwood flooring, which is a manufactured wood product, emerged as a source of metal(loid)s, phthalates, organophosphate flame retardants/plasticizers, and obsolete organochlorine pesticides such as ∑DDT (but not halogenated flame retardants). Many metal(loid)s were significantly correlated with flame-retardant compounds used in building materials and heating systems. Components of heating appliances and heat distribution systems appeared to contribute heat-resistant chemicals and alloys to settled dust. Carpets displayed a dual role as both a source and repository of dust-borne contaminants. Contaminant loadings (<80 µm fraction) were significantly elevated in heavily carpeted homes, particularly those located near industry. Depending on the chemical (and its source), the results show that increased dust mass loading may enrich or dilute chemical concentrations in dust. Research is needed to improve the characterisation of hidden indoor sources such as flame retardants used in building materials and heating systems, or undisclosed ingredients used in common household products, such as air fresheners and products used for companion animals.
Plain language summary
Health Canada is responsible for the assessment and management of health risks to Canadians associated with exposure to products and chemicals in the environment. Settled house dust is a useful medium for evaluating indoor concentrations of chemical contaminants for exposure assessment and for identifying and mitigating contaminant sources. Contaminants in settled dust can originate from a wide range of indoor sources (e.g., building materials, degradation of consumer products, emissions from smoking, cooking etc.), and can be tracked in from outdoor sources. The present study examines relationships amongst house characteristics observed in the Canadian House Dust Study (CHDS; 2007-2010) and uses these relationships to assist in the interpretation of house dust chemistry. The CHDS was designed as a stratified random sampling of 1025 urban, single-family houses across 13 Canadian cities having a population greater than 100,000. During sampling, the technicians documented basic characteristics of each household such as the proximity to industry, house age, uses of specific consumer products, floor covering, occurrence of pets, number of occupants etc. The collected dust was analyzed for hundreds of synthetic organic chemicals and metal(loid)s to provide national baseline concentrations. Numerous synthetic organics were significantly associated with the use of room deodorizers, and with the presence of cats in the home. Components of heating appliances and heat distribution systems appeared to contribute heat resistant chemicals and alloys to settled dust. Dust concentrations of a variety of metal(loid)s, plasticizers, flame retardants and organochlorine pesticides were associated with hardwood flooring. Finally, carpets displayed a dual role as both source and sink of dust-borne contaminants. These findings support Health Canada’s public health advice to regularly clean and remove dust from surfaces in the home, especially surfaces that are accessible to children. The results will help guide development of questionnaires in future house dust studies.
Subject
- Health,
- Health and safety