The effect of reduction measures on concentrations of hazardous semivolatile organic compounds in indoor air and dust of Swedish preschools

Children's exposure to halogenated flame retardants and organophosphate esters through dermal absorption and hand-to-mouth ingestion in Swedish preschools

Children are exposed to endocrine disrupting chemicals (EDCs) through inhalation and ingestion, as well as through dermal contact in their everyday indoor environments. The dermal loadings of EDCs may contribute significantly to children's total EDC exposure due to dermal absorption as well as hand-to-mouth behaviors. The aim of this study was to measure potential EDCs, specifically halogenated flame retardants (HFRs) and organophosphate esters (OPEs), on children's hands during preschool attendance and to assess possible determinants of exposure in preschool indoor environments in Sweden. For this, 115 handwipe samples were collected in winter and spring from 60 participating children (arithmetic mean age 4.5 years, standard deviation 1.0) and analyzed for 50 compounds. Out of these, 31 compounds were identified in the majority of samples. Levels were generally several orders of magnitude higher for OPEs than HFRs, and 2-ethylhexyl diphenyl phosphate (EHDPP) and tris(2-butoxyethyl) phosphate (TBOEP) were detected in the highest median masses, 61 and 56 ng/wipe, respectively. Of the HFRs, bis(2-ethyl-1-hexyl)-2,3,4,5-tetrabromobenzoate (BEH-TEBP) and 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE-209) were detected in the highest median masses, 2.8 and 1.8 ng/wipe, respectively. HFR and/or OPE levels were found to be affected by the number of plastic toys, and electrical and electronic devices, season, municipality, as well as building and/or renovation before/after 2004. Yet, the calculated health risks for single compounds were below available reference dose values for exposure through dermal uptake as well as for ingestion using mean hand-to-mouth contact rate. However, assuming a high hand-to-mouth contact rate, at the 95th percentile, the calculated hazard quotient was above 1 for the maximum handwipe mass of TBOEP found in this study, suggesting a risk of negative health effects. Furthermore, considering additive effects from similar compounds, the results of this study indicate potential concern if additional exposure from other routes is as high.

A randomized controlled trial of a housing intervention to reduce endocrine disrupting chemical exposures in children

Few studies have considered household interventions for reducing endocrine disrupting chemical (EDC) exposures. We conducted a secondary analysis of a randomized controlled trial, originally designed to reduce lead exposure, to evaluate if the intervention lowered EDC exposures in young children. Study participants were children from the Cincinnati, Ohio area (n = 250, HOME Study). Prenatally, families received a housing intervention that included paint stabilization and dust mitigation, or as a control, injury prevention measures. At 24-months, we measured organophosphate esters (OPEs) and phthalates or their metabolites in dust and urine. We measured perfluoroalkyl substances (PFAS) in dust and serum at 24- and 36-months, respectively. We assessed associations between dust and biomarker EDCs using Spearman correlations, characterized EDC mixtures via principal components analysis, and investigated treatment effects using linear regression. To mitigate selection bias, we fit statistical models using inverse probability of retention weights. Correlations between dust EDCs and analogous biomarkers were weak-to-moderate (ρ's ≤ 0.3). The intervention was associated with 23 % (95 % CI: -38, -3) lower urinary DEHP metabolites and, in a per-protocol analysis, 34 % lower (95 % CI: -55, -2) urinary MBZP. Additionally, among Black or African American children, the intervention was associated with lower serum concentrations of several PFAS (e.g., -42 %; 95 % CI: -63, -8 for PFNA). Household interventions that include paint stabilization and dust mitigation may reduce childhood exposures to some phthalates and PFAS in Blacks/African Americans. These findings highlight the need for larger studies with tailored and sustained housing interventions.

Phthalate Acid Esters (PAEs) in Indoor Dust from Decoration Material Stores: Occurrence, Sources, and Health Risks

Phthalate acid esters (PAEs) are one of the most widely used plasticizers globally, extensively employed in various decoration materials. However, studies on the impact of these materials on indoor environmental PAE pollution and their effects on human health are limited. In this study, forty dust samples were collected from four types of stores specializing in decoration materials (flooring, furniture boards, wall coverings, and household articles). The levels, sources, exposure doses, and potential health risks of PAEs in dust from decoration material stores were assessed. The total concentrations of Σ9PAE (the sum of nine PAEs) in dust from all decoration-material stores ranged from 46,100 ng/g to 695,000 ng/g, with a median concentration of 146,000 ng/g. DMP, DEP, DBP, and DEHP were identified as the predominant components. Among all stores, furniture board stores exhibited the highest Σ9PAE (159,000 ng/g, median value), while flooring stores exhibited the lowest (95,300 ng/g). Principal component analysis (PCA) showed that decoration materials are important sources of PAEs in the indoor environment. The estimated daily intakes of PAEs through non-dietary dust ingestion and dermal-absorption pathways among staff in various decoration-material stores were 60.0 and 0.470 ng/kg-bw/day (flooring stores), 113 and 0.780 ng/kg-bw/day (furniture board stores), 102 and 0.510 ng/kg-bw/day (wall covering stores), and 114 and 0.710 ng/kg-bw/day (household article stores). Particularly, staff in wall-covering and furniture-board stores exhibited relatively higher exposure doses of DEHP. Risk assessment indicated that although certain PAEs posed potential health risks, the exposure levels for staff in decoration material stores were within acceptable limits. However, staff in wall covering stores exhibited relatively higher risks, necessitating targeted risk-management strategies. This study provides new insights into understanding the risk associated with PAEs in indoor environments.

Organohalogenated flame retardants and organophosphate esters from home and preschool dust in Sweden: Pollution characteristics, indoor sources and intake assessment

This study analysed settled dust samples in Sweden to assess children's combined exposure to 39 organohalogenated flame retardants (HFRs) and 11 organophosphate esters (OPEs) from homes and preschools. >94 % of the targeted compounds were present in dust, indicating widespread use of HFRs and OPEs in Swedish homes and preschools. Dust ingestion was the primary exposure pathway for most analytes, except BDE-209 and DBDPE, where dermal contact was predominant. Children's estimated intakes of ∑emerging HFRs and ∑legacy HFRs from homes were 1-4 times higher than from preschools, highlighting higher exposure risk for HFRs in homes compared to preschools. In a worst-case scenario, intakes of tris(2-butoxyethyl) phosphate (TBOEP) were 6 and 94 times lower than the reference dose for children in Sweden, indicating a potential concern if exposure from other routes like inhalation and diet is as high. The study also found significant positive correlations between dust concentrations of some PBDEs and emerging HFRs and the total number of foam mattresses and beds/m2, the number of foam-containing sofas/m2, and the number of TVs/m2 in the microenvironment, indicating these products as the main source of those compounds. Additionally, younger preschool building ages were found to be linked to higher ΣOPE concentrations in preschool dust, suggesting higher ΣOPE exposure. The comparison with earlier Swedish studies indicates decreasing dust concentrations for some banned and restricted legacy HFRs and OPEs but increasing trends for several emerging HFRs and several unrestricted OPEs. Therefore, the study concludes that emerging HFRs and OPEs are replacing legacy HFRs in products and building materials in homes and preschools, possibly leading to increased exposure of children.

Seasonal variations of airborne phthalates and novel non-phthalate plasticizers in a test residence in cold regions: Effects of temperature, humidity, total suspended particulate matter, and sources

As a class of plasticizers widely used in consumer products, some phthalate esters (PAEs) have been restricted due to their adverse health effects and ubiquitous presence, leading to the introduction of alternative non-phthalates plasticizers (NPPs) to the market. However, few studies focus on the influence of environmental parameters on the presence of these plasticizers and the potential human health risks for people living in poorly ventilated indoor spaces in cold regions. We investigated the trends of PAEs and NPPs in air in a typical indoor residence in northern China for over one year. The air concentrations of PAEs were significantly higher than those of NPPs (p < 0.05), indicating that PAEs are still the dominant plasticizers currently being used in the studied residence. PAEs showed seasonal fluctuation patterns of the highest levels found in summer and autumn. The temperature and relative humidity dependence for most PAEs and NPPs decreased with decreasing vapor pressure. Concentrations of the high molecular weight NPPs and PAEs positively correlated with total suspended particles (TSP). It is worth noting that the peak concentrations of PAEs and NPPs were found when the haze occurred in autumn. Principal component analysis (PCA) suggested the diverse applications of PAEs and NPPs in the indoor environment. The hazard index (HI) values observed in this study were all below international guidelines (<1); however, the average carcinogenic risk (CR) values for some compounds exceeded acceptable levels (One in a million), which raised concerns about the possibility of carcinogenicity for people living indoors for long periods of time in cold regions.

Volatile Organic Compounds (VOCs) as Environmental Pollutants: Occurrence and Mitigation Using Nanomaterials

Volatile organic compounds (VOCs) comprise various organic chemicals which are released as gases from different liquids or solids. The nature and impact of the health effects are dependent on the VOCs concentrations and, also, on the exposure time. VOCs are present in different household, industrial or commercial and products, but their accumulation in air and water has primarily gained attention. Among VOCs, trichloroethylene and vinyl chloride are the most toxic and carcinogenic compounds. In order to improve the indoor air and water quality, VOCs can be removed via efficient approaches involving nanomaterials, by using techniques such as adsorption, catalysis or photocatalysis. In the recent years, the development of manufacturing procedures, characterization techniques and testing processes has resulted in the growth of na-nomaterials obtaining and applications, creating great possibilities and also a tremendous prov-ocation in applying them for highly efficient VOCs removal. This review is intended to contrib-ute to the improvement of awareness and knowledge on the great potential that nanomaterials have in VOCs removal, in order a to improve indoor and outdoor environment, but also the worldwide water sources.