Halogenated flame retardants (HFRs) were measured in air, floor dust, and surface wipes of electronic devices (e-devices) and hands of participants in 51 Canadian homes to assess the relationship between HFR levels in these matrices and to identify major sources and exposure pathways. Hand-held e-devices had significantly higher concentrations of all HFRs than non-hand-held devices, with the exceptions being decabromodiphenyl ethane (DBDPE) and decabromodiphenyl ether (BDE-209). HFR concentrations on hands were correlated with levels in dust and hand-held e-devices, with the strongest correlations being seen for BDE-47 and -99, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), and bis(3-ethylhexyl) tetrabromophthalate (BEH-TEBP). It is highly unlikely that hand-held devices sampled in 2015 had intentionally added BDE-47 and -99 that were regulated in 2008 in Canada. We hypothesize that hands transferred these chemicals from older products, which act as primary sources, to hand-held devices, which then can act as secondary sources of exposure. This study also found evidence for TVs as a primary source of DBDPE and BDE-209 for dust, hand-held devices, and hands. We suggest that an outdated, overly stringent flammability standard, developed in the 1970s to protect against fires from "instant-on" cathode ray tube TVs, led to elevated levels of these HFRs indoors. Although the standard for TV enclosures has been updated recently, the legacy of the outdated standard persists.

No abstract

Over the last decades, concern has arisen worldwide about the negative impacts of pesticides on the environment and human health. Exposure via dust ingestion is important for many chemicals but poorly characterized for pesticides, particularly in Africa. We investigated the spatial and temporal variations of 30 pesticides in dust and estimated the human exposure via dust ingestion, which was compared to inhalation and soil ingestion. Indoor dust samples were collected from thirty-eight households and two schools located in two agricultural regions in South Africa and were analyzed using high-performance liquid chromatography coupled to tandem mass spectrometry. We found 10 pesticides in dust, with chlorpyrifos, terbuthylazine, carbaryl, diazinon, carbendazim, and tebuconazole quantified in >50% of the samples. Over seven days, no significant temporal variations in the dust levels of individual pesticides were found. Significant spatial variations were observed for some pesticides, highlighting the importance of proximity to agricultural fields or of indoor pesticide use. For five out of the nineteen pesticides quantified in dust, air, or soil (i.e., carbendazim, chlorpyrifos, diazinon, diuron and propiconazole), human intake via dust ingestion was important (>10%) compared to inhalation or soil ingestion. Dust ingestion should therefore be considered in future human exposure assessment to pesticides.

No abstract