--- topic: "House Dust" title: "House Dust as a Chemical Exposure Route" order: 1 description: "House dust carries flame retardants, phthalates, PFAS and pesticides that toddlers swallow. What the studies show and what cleaning and hand washing can do." question: "Is house dust a major source of chemical exposure, and how do you reduce it?" answer: "House dust is likely a major route for flame retardants and phthalates, especially in toddlers; cleaning trials are small and mixed." actions: - "Wash hands with soap and water before eating, and toddlers' hands after floor play: hand-wipe levels tracked toddlers' blood flame retardants [3]; careful washing lowered urinary markers in adults [4]." - "Damp-mop and damp-wipe instead of dry-dusting, and use a HEPA vacuum: guided cleaning halved some flame-retardant markers [4], and assisted cleaning cut toddlers' blood lead 17% in one trial [6]." - "Take shoes off and use a doormat: after a lawn treatment, pesticide residues came in on the applicator and a dog, then settled in floor dust [5]." cautions: - "With a child's raised blood lead, cleaning alone is not enough: dust control did not lower it in trials, so trace the source with your pediatrician and health department [7]." - "Avoid dry-sweeping and dry-dusting, which raise dust into the air. The one trial that saw a benefit used wet mopping, damp sponging and a HEPA vacuum [6]." confidence: 3 confidenceNote: "Dust-to-body links are consistent across several studies, but they are correlations; cleaning trials are small, and the larger lead trials found no benefit." evidenceSummary: rctCount: 1 observationalCount: 8 metaAnalysisCount: 2 totalParticipants: "4,000+" replicated: false newestStudyYear: 2024 references: - id: "1" pmid: "14594359" title: "Phthalates, alkylphenols, pesticides, polybrominated diphenyl ethers, and other endocrine-disrupting compounds in indoor air and dust" authors: "Rudel RA, Camann DE, Spengler JD, et al." year: 2003 journal: "Environ Sci Technol" - id: "2" pmid: "39048064" title: "Meta-analysis of soil and dust ingestion studies" authors: "Cohen J, Hubbard H, Özkaynak H, et al." year: 2024 journal: "Environ Res" - id: "3" pmid: "22763040" title: "Serum PBDEs in a North Carolina toddler cohort: associations with handwipes, house dust, and socioeconomic variables" authors: "Stapleton HM, Eagle S, Sjödin A, et al." year: 2012 journal: "Environ Health Perspect" - id: "4" pmid: "29950671" title: "Flame retardant exposure assessment: findings from a behavioral intervention study" authors: "Gibson EA, Stapleton HM, Calero L, et al." year: 2019 journal: "J Expo Sci Environ Epidemiol" - id: "5" pmid: "11713005" title: "Distribution of 2,4-D in air and on surfaces inside residences after lawn applications: comparing exposure estimates from various media for young children" authors: "Nishioka MG, Lewis RG, Brinkman MC, et al." year: 2001 journal: "Environ Health Perspect" - id: "6" pmid: "10049955" title: "The effect of dust lead control on blood lead in toddlers: a randomized trial" authors: "Rhoads GG, Ettinger AS, Weisel CP, et al." year: 1999 journal: "Pediatrics" - id: "7" pmid: "33022752" title: "Household interventions for secondary prevention of domestic lead exposure in children" authors: "Nussbaumer-Streit B, Mayr V, Dobrescu AI, et al." year: 2020 journal: "Cochrane Database Syst Rev" - id: "8" pmid: "28750223" title: "Associations between flame retardant applications in furniture foam, house dust levels, and residents' serum levels" authors: "Hammel SC, Hoffman K, Lorenzo AM, et al." year: 2017 journal: "Environ Int" - id: "9" pmid: "16082939" title: "Is house dust the missing exposure pathway for PBDEs? An analysis of the urban fate and human exposure to PBDEs" authors: "Jones-Otazo HA, Clarke JP, Diamond ML, et al." year: 2005 journal: "Environ Sci Technol" - id: "10" pmid: "31400598" title: "Children's exposure to phthalates and non-phthalate plasticizers in the home: The TESIE study" authors: "Hammel SC, Levasseur JL, Hoffman K, et al." year: 2019 journal: "Environ Int" - id: "11" pmid: "21334069" title: "Characterisation of human exposure pathways to perfluorinated compounds--comparing exposure estimates with biomarkers of exposure" authors: "Haug LS, Huber S, Becher G, et al." year: 2011 journal: "Environ Int" - id: "12" pmid: "15471731" title: "The association between asthma and allergic symptoms in children and phthalates in house dust: a nested case-control study" authors: "Bornehag CG, Sundell J, Weschler CJ, et al." year: 2004 journal: "Environ Health Perspect" --- House dust collects chemicals shed from furniture, flooring and products, including flame retardants, phthalates, PFAS and pesticides [1]. Young children swallow about 56 to 72 mg of soil and dust a day [2], and the levels on toddlers' hands track their blood levels of some flame retardants [3]. Hand washing, damp cleaning and a doormat may cut exposure [4][5]. ## How it works Flame retardants, plasticizers and other additives are mixed into products rather than locked in, so they shed into air and settle in dust. Dust then reaches you through hands, food, toys and the air you breathe. **What is in it.** In 120 homes, dust held 66 of the 89 hormone-disrupting chemicals tested, from 6 to 42 per home. Flame retardants, phthalates and pesticides were common, including long-banned ones such as DDT and chlordane [1]. **How much gets in.** Pooled studies put average soil-plus-dust intake at 36 to 68 mg a day for infants and 56 to 72 for young children, against 12 to 32 for adolescents and adults [2]. Young children take in about two to six times as much as adults, and their hand-to-mouth habits and floor time load them further. **Flame retardants.** Sofa foam is a source: homes whose foam contained PentaBDE had much more BDE-47 in dust and in residents' blood [8]. In 83 toddlers, blood PBDE levels tracked the amount on their hands (r = 0.57) more closely than the amount in house dust (r = 0.35) [3]. A model of Toronto made dust ingestion the largest PBDE source for everyone beyond infancy [9]. See [flame retardants](/flame-retardants/health-effects-and-exposure). **Phthalates.** In 180 children aged 3 to 6, phthalates in dust and on hands tracked urine metabolites, and children in homes with 100% vinyl flooring had 15 times more of one metabolite [10]. See [phthalates](/phthalates/hormone-disruption-and-health). **PFAS.** For most people food supplies most PFAS (67 to 99% of intake in 41 women), but some got up to about half of theirs indoors [11]. See [reducing PFAS exposure](/pfas/avoiding-pfas). **What helps, ranked** 1. Wash hands with soap and water before eating and after floor play, toddlers' hands included. In 32 mothers, a week of careful hand washing lowered some urinary flame-retardant markers [4]. 2. Damp-mop and damp-wipe, and vacuum with a HEPA-filter machine. A week of guided cleaning lowered some markers by about half [4]; in 113 toddlers, assisted cleaning cut blood lead 17% [6]. 3. Shoes off and a doormat. After lawn spraying, residues were tracked in on the applicator and a dog, then stirred up from floors [5]. 4. When replacing sofas or flooring, look for sofas labeled free of added flame retardants and use less vinyl flooring [8][10]. ## The evidence in detail **Measuring what is there.** Rudel and colleagues sampled air and dust in 120 homes for 89 chemicals identified as endocrine disruptors. Fifty-two were found in air and 66 in dust; 15 exceeded government health-based guidelines, while 28 had no guideline at all [1]. A meta-analysis of U.S. and Canadian studies of soil and dust ingestion gave means of 36 to 68 mg/day for infants and 56 to 72 for young children, with estimates from tracer, biokinetic and activity-pattern studies in line with the U.S. EPA's Exposure Factors Handbook [2]. **Linking dust to the body.** Stapleton and colleagues enrolled 83 children aged 12 to 36 months in North Carolina. PBDEs were in every serum sample (geometric mean 43.3 ng/g lipid for ΣpentaBDE), 98% of handwipes and every dust sample. Serum correlated with handwipes (r = 0.57) and dust (r = 0.35), and handwipe levels, sex, age and father's education explained 39% of the variation in one serum measure [3]. Hammel and colleagues paired furniture foam, dust and serum from a North Carolina cohort. PentaBDE in a sofa went with BDE-47 about 6.4 times higher in dust (p < 0.001) and higher in serum, and a Firemaster 550 component was about three times higher in dust when that mixture was in the foam. Links for TDCIPP and TCIPP were not significant, suggesting other sources [8]. In the TESIE study of 180 children, phthalates in dust and hand wipes correlated with urinary metabolites (rs 0.18 to 0.56); homes with 100% vinyl flooring had 3.5 times more BBP in hand wipes and 4.5 times more in dust [10]. These are cross-sectional correlations, so they cannot fully separate dust from diet or direct contact with products. **Modelling and perspective.** The Toronto model estimated that inadvertent dust ingestion is the largest contributor to PBDE exposure from toddlerhood onward, and that a toddler with high dust intake in a high-PBDE home could take in nearly 100 times the average dose [9]. For PFAS, Haug and colleagues combined measurements for 41 Norwegian women: food supplied 67 to 84% of median PFOA intake and 88 to 99% of PFOS, but the indoor environment accounted for up to around 50% for several individuals, and dust and serum levels were positively associated [11]. **Does it matter for health?** Bornehag and colleagues compared 198 children with persistent allergic symptoms and 202 without, drawn from a cohort of 10,852. Median BBzP in dust was higher in cases (0.15 vs 0.12 mg/g); BBzP was associated with rhinitis and eczema and DEHP with asthma [12]. That is an association, not proof that dust phthalates cause allergy. **Does cleaning help?** Gibson and colleagues assigned 32 mothers for a week to house cleaning or hand washing, then added the other for a second week. Several urinary flame-retardant metabolites fell after each step, by about half in some cases, but hand wipes did not decline significantly across the whole sample, and there was no untreated comparison group [4]. For lead, Rhoads and colleagues randomized 113 urban toddlers to maternal education plus biweekly assisted cleaning (wet mopping, damp sponging, HEPA vacuuming) or to control. After about a year blood lead fell 17% in the intervention group and did not change in controls, and fell 34% where homes were cleaned 20 or more times [6]. Nishioka and colleagues sampled 11 occupied homes before and after a lawn application of 2,4-D. It reached every indoor surface, mainly tracked in by an active dog and the applicator and then resuspended from floor dust; estimated child ingestion from floors was 1 to 10 micrograms a day, about 10 times the pre-application level [5]. **What does not line up.** A Cochrane review of 17 studies (3,282 children) found that dust control did not lower blood lead (mean difference −0.02, 95% CI −0.09 to 0.06; 4 studies, 565 children, moderate-certainty evidence), and neither did education alone [7]. That clashes with the single positive trial [6]; the reviewers call for trials that tackle several lead sources at once [7]. Dust is not the main PFAS route for most people [11]. And the health link for dust chemicals rests mostly on associations [12]. **Bottom line (moderate confidence).** Dust is a real, measurable and sometimes dominant route for flame retardants and phthalates, mostly through hands. Hand washing and damp cleaning are cheap and plausible, and a small study saw biomarker drops, but larger lead trials found no benefit, so do not expect cleaning to fix a known hazard on its own.