Housedust Handout GFA

7/30/2019 Housedust Handout GFA

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Learning Objectives

Acquire knowledge on:

Multimedia exposure

House dust (composition & measurement)

Pollutants in house dust

Population at-risk from pollutants

Characteristics of pollutants

Health effects of pollutants

Identify ways to reduce exposure topollutants in house dust


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What is multimedia exposure?

Exposure to a toxic substance from multiplepathways such as air, water, soil, food, and

breast milk.1

Substances may come into contact withhumans through various media: air (outdoor

and indoor), workplace, water, foodstuffs, andhousehold chemicals.2

Sources:1http://coalitionforcleanair.org/air-pollution-glossary (Accessed Nov. 6,2012)2Bustueva KA. 1991. Some Specifications of Multimedia Exposure Monitoring

Assessment. In RG Tardiff & B Goldstein (eds.) Methods for Assessing Exposure

of Human and Non-Human Biota.


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What is multimedia exposureanalysis?

Multimedia exposure analysis:

determines how often individuals are exposed toconcentration of pollutants, and the contribution ofindividual sources to the total exposure; and

creates a distribution that provides information on thepercent of individuals exposed to differentconcentration levels for an averaging time of interest.

Source: JW Roberts & WR Ott. 2007. Exposure to Pollutants from House Dust. In WR Ott, ACSteinemann & LA Wallace (eds.) Exposure Analysis.


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What is house dust?

A heterogeneous mixture of substances fromvarious sources, including tracked-in orresuspended soil particles, fibers (artificial ornatural), atmospheric deposition of particulates,hair, molds, pollen, allergens, bacteria, viruses,

arthropods, ash, soot, animal fur and dander,smoke, skin particles, cooking and heatingresidues, building components and among others

(Pastenbauch, Finley & Long, 1997)

House dust also contains pollutants from windowcleaners, laundry detergents, spot removers,plastics, electronics and carpeting

(Rudel et al., 2003)


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House dustserves as a

reservoirfor

chemicals either tracked-inor used indoors


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Source: PJ Lioy, NC Freeman & JR Millette. 2002. Dust: A Metric for Use in Residential and Building Exposure

Assessment and Source Characterization. Environmental Health Perspectives, 110 (10).

Composition of House Dust


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Relative Contribution of Soil in House Dust

Source: AG Oomen & JPA Lijzen. 2004. Relevancy of human exposure via house dust to contaminants

lead and asbestos. RIVM report 711701037.


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Difference between Dust and Soil

Soil. Particles of unconsolidated mineral and/or organicmatter from the earths surface that are located outdoors, orare used indoors to support plant growth. It includes particlesthat have settled onto outdoor objects and surfaces (outdoorsettled dust).

Indoor Settled Dust. Particles in building interiors that have

settled onto objects, surfaces, floors, and carpeting. Theseparticles may include soil particles that have been tracked orblown into the indoor environment from outdoors as well asorganic matter.

Outdoor Settled Dust. Particles that have settled onto

outdoor objects and surfaces due to either wet or drydeposition. Note that it may not be possible to distinguishbetween soil and outdoor settled dust, since outdoor settleddust generally would be present on the uppermost surfacelayer of soil.


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Characteristics of House Dust thatInfluence Exposure Potential

Dust particle size distribution

Concentration of contaminants in dust relative

to exterior soilsBioavailability of the fine versus the larger

particles

Indoor environmental factors


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Particle Size Distribution

House dust is composed of smaller particles thansoil

Size affects deposition or mobility rates

50% of house dust have soil particles greater than150m in diameter (Roberts et al., 1991)

Stomping experiment by Ott showing thatstomping activity increased the concentration ofPM5 or smaller at 30 inches above the floor and the

level returned to normal only after 1.5 hours Fine particles adhere to skin more easily and

effectively thereby increasing exposure potential


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Ratio of Contaminants in Dust andSoil

Contaminants appear to be greater in house dustcompared to exterior soil

Roberts et al. (1992) explained that smallparticles have a higher surface area and toxicityper unit mass


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Bioavailability of Fine Particles

Contaminants appear to be greater in house dustcompared to exterior soil

Roberts et al. (1992) explained that smallparticles have a higher surface area and toxicityper unit mass

Fine particles result in an increased absorbeddose


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Indoor Environmental Factors

Indoor environment protects pollutants from thedegradation, aging or dispersion

Many chemicals found in house dust can persistindoors for a long time because there is no rain,sun, or other environmental elements that helpto break down and get rid of these agents

The variability in the particle loading from insidevs. outside the home and among homes is

dependent on home occupants activities,presence of pets and steps taken to reduce housedust (e.g. cleaning intensity and method)


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Measuring House Dust

Filtering method

Wiping method

Surface wipe sampling

Rug and carpet sampling

Vacuum method

Personal (fine particle) monitor


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Measuring House Dust


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Who is At-Risk from House DustPollutants?

Infants and young children are particularlyvulnerable to chemical exposures from housedust because they frequently tend to place theirhands or other objects in their mouths andbecause they spend a large portion of their timeon the floor exploring their environment

Anyone with asthma or other respiratoryproblems, or a weakened immune system shouldmake every effort to reduce household dust


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Heavy metals Pesticides

Alkylphenols nonylphenol, octylphenol & their

derivatives

Brominated flameretardants polybrominated diphenyl ethers or PBDEs,

hexabromocyclododecane or HBCD &tetrabromobisphenol-A or TBBP-A

Organotin compounds butyltins, octyltins, & tri-butyltin or TBT

Phthalate esters

Short-chain chlorinatedparaffins (SCCPs)

Endotoxins/AllergensOrganochlorine

polychlorinated biphenyl (PCB) congeners,chlordane, DDT(dichlorodiphenyltrichloroethane) , DDE(dichlorodiphenyldichloroethylene),methoxychlor & pentachlorophenol

Polycyclic aromatichydrocarbons (PAHs)

Pollutants in House Dust


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What is Lead?

Lead exists in theearths crust, andoccurs naturally in theenvironment through avariety of mechanismsincluding volcanic

emissions andgeochemicalweathering.

Lead has been put tomany uses and is

important in plumbingmaterials, gasolineadditives, batteries,pigments andammunition.

What are the healtheffects of Lead?

Source: L. Fewtrell, R. Kaufmann & AP Ustun. 2003. Lead: Assessingthe environmental burden of disease at national and local levels. WHOEnvironmental Burden of Disease Series No. 2. Retrieved from

www.who.int/quantifying_ehimpacts/publications/en/leadebd2.pdf


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The loss of IQpoints is quantified

assuming a linearrelationship of 1.3IQ points lost per 5g/dl of blood lead

between 520g/dl (fig. 2)

1.59% ofpopulation entersMMR cut-off of 70due to lead (fig. 3)


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Lead Standards in Dust and Soil:(USEPA, 2001)

Dust-lead hazard 40 g/ft2 on floors and250 g/ft2 on window sills. The floor standardapplies to carpeted surfaces as well as barefloors.

Soil-lead hazard 400 parts per million(ppm) for bare soil in play areas and 1,200ppm average in the rest of the yard.

Deteriorated lead-based paint (LBP) deterioration larger than 20 ft2 exterior and 2

ft2

interior or damage to 10% of the totalsurface area of interior small surface areacomponents.

LBP is a paint of any surface coatingcontaining lead > 1 mg/cm2


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Source: NJ Simcox, RA Fenske, SA Wols, IC Lee & DA Kalman. 1995. Pesticides in Household Dust and Soil:

Exposure Pathways fro Children of Agricultural Families. Environmental health Perspectives, 103 (12).

Pesticides in House Dust


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Alkyphenols (APs), are non-halogenated chemicalsmanufactured almost exclusively to produce alkylphenol

ethoxylates (APEs), a group of non-ionic surfactants. Themost widely used APEs are ethoxylates of nonylphenol(NPEs) and, to a lesser extent, octylphenol (OPEs).

NPEs have been used as surfactants, emulsifiers,dispersants and/or wetting agents in a variety of industrialand consumer applications. The largest share (almost 30%)

was used in industrial and institutional cleaning products(detergents), although uses such as emulsifiers (11%),textile finishers (10%), leather finishers (7%) and ascomponents of pesticides and other agricultural products(6%) and water-based paints (5%) were also significant(OSPAR 2001).

A substantial proportion (16%) was reportedly used inother niche markets (including as ingredients incosmetics, shampoos and other personal care products), orin glues and sealants.

NP derivatives are reportedly also used as antioxidants insome plastics (Guenther et al. 2002).

Alkyphenols


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The main hazards associated with APEs resultfrom their partial degradation to shorter-chainethoxylates and to the parent APs themselves(i.e. NP and OP), both of which are toxic toaquatic organisms.

Hazards to human health remain unclear,although recent studies have highlightedconcerns directly relevant to humans. Forexample, Chitra et al. (2002), and Adeoya-

Osiguwa et al. (2003), describe effects onmammalian sperm function, while DNA damagein human lymphocytes has also recently beendocumented (Harreus et al. 2002).

Alkyphenols: Health effects


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Brominated flame retardants (BFRs) are a groupof brominated organic substances that have aninhibitory effect on the ignition of combustibleorganic materials. The most widely used BFRs aretetrabromobisphenol-A (TBBP-A),hexabromocyclododecane (HBCDD), andpolybrominated diphenylethers (PBDEs) (DeWinter-Sorkina et al., 2006).

BFRs are applied to textiles, wiring, furniture,

industrial paints and incorporated into plasticsand foams, and they are commonly used inelectronic products to reduce the flammability ofthe product.

Brominated flame retardants


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Brominated flame retardants in Air vsDust

Source: H Fromme et al. 2009. Human exposure to polybrominated diphenyl ethers, as evidenced by data from a

Duplicate diet study, indoor air, house dust and biomonitoring in Germany. Environment International, 35,

1125-1135.


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A number of studies have suggested that PBDE are highlypersistent and bioaccumulative

Some animal studies have suggested that the criticaleffects are exhibited on the liver, in development,neurodevelopment and in the endocrine system (NICNAS,

2001; HC, 2006; Kuriyama et al., 2007). For example, ratsthat are pre- and perinatally exposed to relatively lowdoses of pentabrominated BDE 99 presented disturbedhormone levels

While their acute toxicity is considered to be low, chronicexposure (especially in the womb) has been shown tointerfere with brain and skeletal development in rats(Eriksson et al. 1999), which may in turn lead topermanent neurological effects (Eriksson et al. 2001)

Helleday et al. (1999), report genotoxic effects for bothPBDEs and HBCD in mammalian cell lines

Brominated flame retardants:Health effects


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Chemical compounds based on tin with hydrocarbon

substituents primarily used in five major commercialapplications: PVC heat stabilizers, biocides, catalysts,agrichemicals and glass coatings.

Triorganotins have a high toxicity and can be powerfulfungicides and bactericides, depending on the organic

group present. Tributyltins(TBT) are industrial biocides used in

antifouling paints and in wood treatment andpreservation. Tributyltins are also used as disinfectants,molluscicides, antifungal action in textiles and industrialwater systems such as cooling tower and refrigeration

water systems, wood pulp and paper mill systems, andbreweries. Many of these applications have been phasedout because of the high aquatic toxicity of tributyltins.

Triphenyltins are used as fungicides, miticides andacaricides.

Source: AG Oomen, PJCM Janssen, A Dusseldorp, CW Noorlander. 2008. Exposure to chemicals via house dust.RIVM report 609021064.

Organotins


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Organotins have been demonstrated to haveimmunotoxic and teratogenic (developmental)properties also in mammalian systems (Kergosienand Rice 1998), with dibutyltins (DBT) againfrequently appearing more toxic than TBT (Emaet al. 1995, De Santiago and Aguilar-Santelises1999).

DBT is neurotoxic to mammalian brain cells(Eskes et al. 1999).

Kumasaka et al. (2002) have described toxiceffects on testes development in mice.

Organotins: Health effects


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Phthalates or phthalate esters, are a group ofchemicals that are mainly used as softeners inflexible PVC products. Phthalates can be found ina broad range of consumer products likepackaging materials, wallpapers, furnishings,clothing and toys, as well as ingredients incosmetics and perfumes.

Source: AG Oomen, PJCM Janssen, A Dusseldorp, CW Noorlander. 2008. Exposure to chemicals via house dust.

RIVM report 609021064.

Phthalate esters


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DEHP (diethylhexyl phthalate), is a knownreproductive toxin, interfering with testesdevelopment in mammals.

Indeed, its toxicity to the developing male

reproductive system has been recognised formore than 50 years (Park et al. 2002).

Observed toxicity is due mainly to the compoundMEHP, formed in the body as a metabolite ofDEHP, and appears to impact on many aspects ofdevelopment and liver function, includinghormone metabolism and immune function(Dalgaard et al. 2001, Wong and Gill 2002).

Phthalate esters: Health effects


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Source: MH Ward et al. 2009. Residential Exposure to Polychlorinated Biphenyls and Organochlorine Pesticides

and Risk of Childhood Leukemia. Environmental Health Perspectives, 117 (6).

Organochlorine


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Polycyclic aromatic hydrocarbons (PAHs) are a group ofchemicals composed of two or more fused aromaticrings made up of carbon and hydrogen.

PAHs are formed by the incomplete combustion of coal,oil, petrol, wood, tobacco, charbroiled meats, garbage,or other organic materials.

PAHs are present in tobacco smoke, smoke from homeheating (burning wood or oil), char-grilled food andcreosote treated wood products.

PAHs are also present in the soil where coal, wood,petrol or other products have been burned.

Most of the PAHs are considered genotoxic carcinogens.A few are used in medicines, and to make dyes, plastics,and pesticides.

Naphthalene is used in making dyes, explosives, plastics,lubricants, and moth repellent.

Anthracene is used in dyes, insecticides and woodpreservatives.

Source: AG Oomen, PJCM Janssen, A Dusseldorp, CW Noorlander. 2008. Exposure to chemicals via house dust.

RIVM report 609021064.

PAHs


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The carcinogenicity of certain PAHs is wellestablished in laboratory animals. Researchershave reported increased incidences of skin, lung,bladder, liver, and stomach cancers, as well asinjection-site sarcomas, in animals.

Animal studies show that certain PAHs also canaffect the hematopoietic and immune systemsand can produce reproductive, neurologic, anddevelopmental effects.

PAHs: Health effects


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PAHs: Health effects


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Source: PS Thorne, RD Cohn, D Mav, SJ Arbes & DC Zeldin. 2009. Predictors of Endotoxin Levels in US Housing.

Environmental Health Perspectives, 117 (5).

Endotoxins in the Home


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Control Measures for Exposure toPollutants in House Dust : RemovingDust Safely and Effectively

Vacuum frequently and use a vacuum fitted with a HEPA (highefficiency particulate air) filter.

Wet mop uncarpeted floors frequently to prevent dust from

accumulating (dry mopping can kick up dust that simply resettles).

Wipe furniture with a wet or microfiber cloth. Microfiber clothswork well because their smaller fibers cling to the particles.

Caulk and seal cracks and crevices to prevent dust fromaccumulating in hard-to-reach places.

Equip your forced-air heating or cooling system with high-qualityfilters and change them frequently to keep them working well.

Keep electronic equipment dust-free by damp dusting it frequently.

Pay special attention to places where little kids crawl, sit and play.


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Control Measures for Exposure toPollutants in House Dust : Removing

Dust Safely and Effectively

Feather dusters have no value because theysimply spread dust around.

Check the vacuum cleaners:

Is the bag full?

Is the belt worn or broken?

Is the brush worn? Is there a leak through the nozzle?

Does it have an agitator?


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Control Measures for Exposure toPollutants in House Dust : Creating LessToxic Dust

Leave your shoes at the door and use a natural doormat.

Inspect foam products made between 1970 and 2005 --they're likely to contain PBDEs.

Choose home electronics without PBDEs. Stick to products made with natural fibers that are naturally

fire resistant and may contain fewer chemicals -- like woodfurniture, cotton, down and wool.

Clean up quickly and thoroughly when you finish a home

improvement project, since these can involve dust (fromsanding or drilling) and toxic products (like lead, PCBs and fireretardants).

Source: http://www.ewg.org/healthyhometips/toxicchemicalsinhousedust
http://www.ewg.org/healthyhometips/toxicchemicalsinhousedusthttp://www.ewg.org/healthyhometips/toxicchemicalsinhousedust

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Housedust Handout GFA