Indoor phthalate exposure and contributions to total intake among pregnant women in the SELMA study

Phthalates are widely used in consumer products. Exposure to phthalates can lead to adverse health effects in humans, with early-life exposure being of particular concern. Phthalate exposure occurs mainly through ingestion, inhalation, and dermal absorption. However, our understanding of the relative importance of different exposure routes is incomplete. This study estimated the intake of five phthalates from the residential indoor environment for 455 Swedish pregnant women in the SELMA study using phthalate mass fraction in indoor dust and compares these to total daily phthalate intakes back-calculated from phthalate metabolite concentrations in the women's urine. Steady-state models were used to estimate indoor air phthalate concentrations from dust measurements. Intakes from residential dust and air made meaningful contributions to total daily intakes of more volatile di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), and di-iso-butyl phthalate (DiBP) (11% of total DEP intake and 28% of total DnBP and DiBP intake combined). Dermal absorption from air was the dominant pathway contributing to the indoor environmental exposure. Residential exposure to less volatile phthalates made minor contributions to total intake. These results suggest that reducing the presence of low molecular weight phthalates in the residential indoor environment can meaningfully reduce phthalate intake among pregnant women.     

A general mechanistic model for predicting the fate and transport of phthalates in indoor environments

A mechanistic model that considers particle dynamics and their effects on surface emissions and sorptions was developed to predict the fate and transport of phthalates in indoor environments. A controlled case study was conducted in a test house to evaluate the model. The model‐predicted evolving concentrations of benzyl butyl phthalate in indoor air and settled dust and on interior surfaces are in good agreement with measurements. Sensitivity analysis was performed to quantify the effects of parameter uncertainties on model predictions. The model was then applied to a typical residential environment to investigate the fate of di‐2‐ethylhexyl phthalate (DEHP) and the factors that affect its transport. The predicted steady‐state DEHP concentrations were 0.14 μg/m³ in indoor air and ranged from 80 to 46 000 μg/g in settled dust on various surfaces, which are generally consistent with the measurements of previous studies in homes in different countries. An increase in the mass concentration of indoor particles may significantly enhance DEHP emission and its concentrations in air and on surfaces, whereas increasing ventilation has only a limited effect in reducing DEHP in indoor air. The influence of cleaning activities on reducing DEHP concentration in indoor air and on interior surfaces was quantified, and the results showed that DEHP exposure can be reduced by frequent and effective cleaning activities and the removal of existing sources, though it may take a relatively long period of time for the levels to drop significantly. Finally, the model was adjusted to identify the relative contributions of gaseous sorption and particulate‐bound deposition to the overall uptake of semi‐volatile organic compounds (SVOCs) by indoor surfaces as functions of time and the octanol‐air partition coefficient (K_oa) of the chemical. Overall, the model clarifies the mechanisms that govern the emission of phthalates and the subsequent interactions among air, suspended particles, settled dust, and interior surfaces. This model can be easily extended to incorporate additional indoor source materials/products, sorption surfaces, particle sources, and room spaces. It can also be modified to predict the fate and transport of other SVOCs, such as phthalate‐alternative plasticizers, flame retardants, and biocides, and serves to improve our understanding of human exposure to SVOCs in indoor environments.     

Beyond phthalates: Gas phase concentrations and modeled gas/particle distribution of modern plasticizers

The ongoing health debate about polymer plasticizers based on the esters of phthalic acid, especially di(2-ethylhexyl) phthalate (DEHP), has caused a trend towards using phthalates of lower volatility such as diisononyl phthalate (DINP) and towards other acid esters, such as adipates, terephthalates, citrates, etc. Probably the most important of these so-called “alternative” plasticizers is diisononyl cyclohexane-1,2-dicarboxylate (DINCH). In the indoor environment, the continuously growing market share of this compound since its launch in 2002 is inter alia apparent from the increasing concentration of DINCH in settled house dust. From the epidemiological point of view there is considerable interest in identifying how semi-volatile organic compounds (SVOCs) distribute in the indoor environment, especially in air, airborne particles and sedimented house dust. This, however, requires reliable experimental concentration data for the different media and good measurements or estimates of their physical and chemical properties. This paper reports on air concentrations for DINP, DINCH, diisobutyl phthalate (DIBP), diisobutyl adipate (DIBA), diisobutyl succinate (DIBS) and diisobutyl glutarate (DIBG) from emission studies in the Field and Laboratory Emission Cell (FLEC). For DINP and DINCH it took about 50 days to reach the steady-state value: for four months no decay in the concentration could be observed. Moreover, vapor pressures p₀ and octanol-air partitioning coefficients K_OA were obtained for 37 phthalate and non-phthalate plasticizers from two different algorithms: EPI Suite and SPARC. It is shown that calculated gas/particle partition coefficients K_p and fractions can widely differ due to the uncertainty in the predicted p₀ and K_OA values. For most of the investigated compounds reliable experimental vapor pressures are not available. Rough estimates can be obtained from the measured emission rate of the pure compound in a microchamber as is shown for di-n-butyl phthalate (DnBP), di(2-ethylhexyl) adipate(DEHA), tri(octyl) trimellitate (TOTM) and DEHP.     

Determining source strength of semivolatile organic compounds using measured concentrations in indoor dust

Consumer products and building materials emit a number of semivolatile organic compounds (SVOCs) in the indoor environment. Because indoor SVOCs accumulate in dust, we explore the use of dust to determine source strength and report here on analysis of dust samples collected in 30 US homes for six phthalates, four personal care product ingredients, and five flame retardants. We then use a fugacity‐based indoor mass balance model to estimate the whole‐house emission rates of SVOCs that would account for the measured dust concentrations. Di‐2‐ethylhexyl phthalate (DEHP) and di‐iso‐nonyl phthalate (DiNP) were the most abundant compounds in these dust samples. On the other hand, the estimated emission rate of diethyl phthalate is the largest among phthalates, although its dust concentration is over two orders of magnitude smaller than DEHP and DiNP. The magnitude of the estimated emission rate that corresponds to the measured dust concentration is found to be inversely correlated with the vapor pressure of the compound, indicating that dust concentrations alone cannot be used to determine which compounds have the greatest emission rates. The combined dust‐assay modeling approach shows promise for estimating indoor emission rates for SVOCs.     

Predicting dermal absorption of gas‐phase chemicals: transient model development,evaluation, and application

A transient model is developed to predict dermal absorption of gas‐phase chemicals via direct air‐to‐skin‐to‐blood transport under non‐steady‐state conditions. It differs from published models in that it considers convective mass‐transfer resistance in the boundary layer of air adjacent to the skin. Results calculated with this transient model are in good agreement with the limited experimental results that are available for comparison. The sensitivity of the modeled estimates to key parameters is examined. The model is then used to estimate air‐to‐skin‐to‐blood absorption of six phthalate esters for scenarios in which (A) a previously unexposed occupant encounters gas‐phase phthalates in three different environments over a single 24‐h period; (B) the same as ‘A’, but the pattern is repeated for seven consecutive days. In the 24‐h scenario, the transient model predicts more phthalate absorbed into skin and less absorbed into blood than would a steady‐state model. In the 7‐day scenario, results calculated by the transient and steady‐state models converge over a time period that varies between 3 and 4 days for all but the largest phthalate (DEHP). Dermal intake is comparable to or larger than inhalation intake for DEP, DiBP, DnBP, and BBzP in Scenario ‘A’ and for all six phthalates in Scenario ‘B’.     

Emission of phthalates from PVC and other materials

The main objective of this study was to generate quantitative and qualitative emission data on phthalates from different materials. To achieve this the existing (Chamber for Laboratory Investigations of Materials, Pollution and Air Quality) Climpaq-based procedure for simplified measurements of emissions of plasticizer from PVC and other plasticized materials was modified. It was applied to a range of products. Some of them were suspected of contributing to the indoor concentration of plasticizers. The emissions from PVC flooring, polyolefine flooring, a refrigerator list, two electric cables, PVC skirting and floor wax were studied in separate Climpaqs. The emission from the PVC flooring in the Climpaq was compared with results from the ultra-small chamber Field and Laboratory Emission Cell (FLEC). Sampling and analysis methods were optimized to measure plasticizers. Samples were taken in exhaust air from the chambers after 6, 35, 62, 105, and 150 days from the start of the experiment. PVC flooring was tested for an additional 100 days. Polyolefine covered with wax resulted in an air concentration of 22 microg/m3 of dibutylphthalate (DBP), which is two orders of magnitude larger than any other materials, but did not emit di(2-ethylhexyl)phthalate (DEHP). The other materials resulted in max concentration of approximately 1 microg/m3 of DEHP and low emissions of DBP. The concentration of DEHP in each chamber increased slowly to a rather stable level which was reached after 150 days. DBP concentrations in the chambers with PVC skirting, PVC flooring, polyolefine and floor wax reached their quasi-static equilibrium after 60 days. The modified method did not create sufficient data for the calculation of emission rates. Adsorption of emission on chamber surfaces made it impossible to use the first part of the experiment for emission rate calculation. When the concentration had stabilized, it was found to be almost identical and independent of chamber and ventilation rate. Emission rates were reduced at high concentrations probably because the concentration in the material was near equilibrium with the concentration in the chamber air.     

Phthalic esters in the indoor environment--test chamber studies on PVC-coated wallcoverings

Phthalic acid esters are important additives in polyvinyl chloride (PVC) products. Since PVC plastisoles for the production of wallcoverings contain about 30% phthalic acid esters, it is a crucial question whether these products can contribute to the pollution of the indoor environment. In this study, the emission of several technically relevant phthalates from PVC-coated wallcoverings were measured in emission test chambers under standard room conditions. During a 14-day test period, both the chamber air concentrations and the condensation on a cooled plate (fogging) were determined. In the chamber air, maximum concentrations of 5.1 micrograms/m3 for di-n-butylphthalate (DBP), 2.08 micrograms/m3 for di-pentylphthalate (DPP) and 0.94 microgram/m3 for di-(2-ethylhexyl)phthalate (DEHP) were found. After 14 days of exposure, up to 60.4 micrograms DEHP and 17.7 micrograms DPP could be quantified on the cooled plates of the fogging apparatus. The amounts of DBP and DIBP were significantly lower. A simple exposure calculation indicated no specific risk of an increased phthalate exposure in rooms with PVC wallcoverings.     

Atmospheric fate of phthalate esters in an urban area (Paris-France)

The atmospheric fate of six phthalate esters was investigated in the urban area of Paris (France). Total atmospheric levels (ng m-3) were as follows: DMP, 0.5; DEP, 10.7; DnBP, 22.2; BBP, 4.6; DEHP, 18.9; and DnOP, 0.5 ng m-3, showing a predominance of DnBP and next, DEHP. They are mainly present in the vapour phase, from 93.8% to 64.9%, particularly for the esters with alkyl chain length of less than six C. An inverse correlation was found between the vapour phase concentrations and the molecular weight and also a direct correlation between the vapour phase concentrations and the log [vapour pressure] of the compounds. Seasonal variations were displayed by principal component analysis (PCA), due to significant correlation between phthalate concentrations and air temperature. Rain water concentrations (ng L-1) were as follows: DMP, 116; DEP, 333; DnBP, 592; BBP, 81; DEHP, 423; and DnOP, 10. PCA analysis showed a seasonal variation of these concentrations correlated to the air temperature. The experimental water/air scavenging ratio was calculated and was in accordance with the theoretical one obtained from the vapour pressure and the Henry's law constant for each phthalate ester. The global trend was a decrease of the washout coefficient in relation with the rise of alkyl chain length. Yearly balances for rainwater and bulk deposition allowed the estimation of dry deposits that represented about half of total. Our findings highlight the major part played by particles in atmospheric deposition processes.     

Phthalate removal throughout wastewater treatment plant: Case study of Marne Aval station (France)

The fate of six phthalates: dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), butyl benzyl phthalate (BBP), bis (2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) was investigated throughout wastewater treatment processes in the wastewater treatment plant (WWTP) of Marne Aval (France). That plant treats wastewater from a highly populated area and was used as a pilot station for development of nitrification processes.In wastewater, at each step of treatment, DEHP was always the major compound (9 to 44 µg L^− 1), followed by DEP (1.6 to 25 µg L^− 1). Other phthalates averaged 1 µg L^− 1 and DnOP remained close to the detection limit in nearly all cases.In sludge, the prevailing compound was also DEHP (72 µg g^− 1) which is consistent with its tendency to get sorbed upon suspended matter (SM). DnOP came in third, in relation with its resistance to biodegradation.For the studied period, the removal efficiency of DEHP from wastewater was about 78%. That removal seemed to proceed rather from particle settling than from biodegradation. A highly significant correlation (p < 0.001) was found between DEHP and SM concentrations throughout treatment processes. The other compounds: DMP, DEP, DnBP and BBP, displayed satisfactory efficiencies ranging from 68 to over 96% for the lighter ones obviously more easily degraded.Under rainy periods, the plant discharge impact upon Marne River quality in terms of phthalate fluxes, appeared to be minor as compared to the amount brought by the storm overflows in the same area. Downstream of the WWTP discharge, DEHP concentration remained under the European norm for surface water (NQE: 1.3 µg L^− 1).Our study documents the behaviour of phthalate esters throughout a WWTP which treatment device is used by 55% of the WWTP in the river Seine basin.     

Semi‐volatile organic compounds in the air and dust of 30 French schools: a pilot study

The contamination of indoor environments with chemical compounds released by materials and furniture, such as semi‐volatile organic compounds (SVOCs), is less documented in schools than in dwellings—yet children spend 16% of their time in schools, where they can also be exposed. This study is one of the first to describe the contamination of the air and dust of 90 classrooms from 30 nursery and primary schools by 55 SVOCs, including pesticides, phosphoric esters, musks, polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs), phthalates, and polybromodiphenylethers (PBDEs). Air samples were collected using an active sampling method, and dust samples were collected via two sampling methods (wiping and vacuum cleaning). In air, the highest concentrations (median >100 ng/m³) were measured for diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), diethyl phthalate (DEP), bis(2‐ethylhexyl) phthalate (DEHP), and galaxolide. In dust, the highest concentrations (median >30 μg/g) were found for DEHP, diisononyl phthalate (DiNP), DiBP, and DBP. An attempt to compare two floor dust sampling methods using a single unit (ng/m²) was carried out. SVOC concentrations were higher in wiped dust, but frequencies of quantification were greater in vacuumed dust.     

Phthalates and nonylphenols in urban runoff: Occurrence, distribution and area emission factors

The urban water system is believed to be an important sink for the nonpoint-source pollutants nonylphenols and phthalates. The presence of nonylphenols (NPs), nonylphenol ethoxylates (NPEOs), and eight phthalates was analyzed in urban stormwater and sediment from three catchment areas in Sweden. Emission loads for these substances were then calculated for a specific urban catchment area. In addition, substance distribution in road runoff passing through a sedimentation facility was modeled using a modified QWASI-model for chemical fate. High concentrations of DEHP, DIDP and DINP (≤ 48, 66 and 200 µg/g dw, respectively) as well as nonylphenol mono- and di-ethoxylate (6.6 and 20 µg/g dw, respectively) were found in the sediment. Aqueous concentrations of the pollutants varied considerably; branched NP was detected in concentrations up to 1.2 µg/L, whereas di(2-ethylhexyl) phthalate (DEHP), diisodecyl phthalate (DIDP), and diisononyl phthalate (DINP) were the most frequently detected phthalates in concentrations up to 5.0, 17 and 85 µg/L, respectively. The fate modeling demonstrated that predicted substance levels in water agreed well with measured levels, whereas the modeled sediment levels were underestimated. Calculation of catchment area emission factors from an urban highway environment revealed that as much as 2.1 kg of total phthalates and 200 g of NP and NPEOs may be emitted per hectare and year. The results indicate that all monitored phthalates, branched NPs and lower NPEOs are present in Swedish urban water systems. The long-chain phthalates DIDP and DINP are believed to occur at higher concentrations than other phthalates because of their higher environmental persistence and their increasing use in Sweden.     

Microcosm investigations of phthalate behaviour in sewage treatment biofilms

Discharge from sewage works has been shown to be an important source of phthalates into the environment which is of major concern because some are toxic, suspected endocrine disruptors and recalcitrant. Laboratory trickle filter microcosms (continuous and re-circulating flow) were constructed and operated to investigate the biodegradation and adsorption of phthalates and also to isolate phthalate degrading microorganisms. It was found that adsorption was critical for the removal of both DEP (77.5%) and DEHP (55.7%) in continuous flow microcosms. The proportion of phthalates removed by biodegradation in the continuous flow microcosms was estimated. Re-circulating flow microcosms improved the removal of DEHP compared to continuous flow microcosms. Microcosm biofilm used for an enrichment culture on phthalate media isolated a varied group of microbes including Gram negative and Gram positive bacteria, yeasts and fungi. Bacteria species with all the necessary enzymes to degrade phthalic acid were isolated.     

Phthalate metabolites in urine samples from Beijing children and correlations with phthalate levels in their handwipes

Little attention has been paid to dermal absorption of phthalates even though modeling suggests that this pathway may contribute meaningfully to total uptake. We have concurrently collected handwipe and urine samples from 39 Beijing children (5–9 years) for the purpose of measuring levels of five phthalates in handwipes, corresponding concentrations of eight of their metabolites in urine, and to subsequently assess the contribution of dermal absorption to total uptake. In summer sampling, DEHP was the most abundant phthalate in handwipes (median: 1130 μg/m²), while MnBP was the most abundant metabolite in urine (median: 232 ng/ml). We found significant associations between the parent phthalate in handwipes and its monoester metabolite in urine for DiBP (r = 0.41, P = 0.01), DnBP (r = 0.50, P = 0.002), BBzP (r = 0.48, P = 0.003), and DEHP (r = 0.36, P = 0.03). Assuming that no dermal uptake occurred under clothing‐covered skin, we estimate that dermal absorption of DiBP, DnBP, BBzP, and DEHP contributed 6.9%, 4.6%, 6.9%, and 3.3%, respectively, to total uptake. Assuming that somewhat attenuated dermal uptake occurred under clothing‐covered skin, these estimates increase to 19%, 14%, 17%, and 10%. The results indicate that absorption from skin surfaces makes a meaningful contribution to total phthalate uptake for children and should be considered in future risk assessments.     

Phthalates in indoor dust in Kuwait: implications for non‐dietary human exposure

Phthalates are semivolatile organic compounds with a ubiquitous environmental distribution. Their presence in indoor environments is linked to their use in a variety of consumer products such as children's toys, cosmetics, food packaging, flexible PVC flooring among others. The goal of this study was to investigate the occurrence and concentration of phthalates in dust from homes in Kuwait and to assess non‐dietary human exposure to these phthalates. Dust samples were randomly collected from 21 homes and analyzed for eight phthalates. The concentrations of total phthalates were log normally distributed and ranged from 470 to 7800 μg/g. Five phthalates [Di(2‐ethylhexyl) phthalate (DEHP), Di‐n‐octyl phthalate (DnOP), Di‐n‐butyl phthalate (DBP), Benzyl butyl phthalate (BzBP), and Dicyclohexyl phthalate (DcHP)] were routinely detected. The major phthalate compound was DEHP at a geometric mean concentration of 1704 μg/g (median, 2256 μg/g) accounting for 92% of the total phthalates measured. Using the measured concentrations and estimates of dust ingestion rates for children and adults, estimated human non‐dietary exposure based on median phthalate concentrations ranged from 938 ng/kg‐bd/day for adults to 13362 ng/kg‐bd/day for toddlers. The difference in exposure estimates between children and adults in this study supports previous reports that children are at greater risk from pollutants that accumulate indoors.     

The occurrence and removal of phthalates in a trickle filter STW

This study investigated the fate of phthalates in a trickle filter sewage treatment works. A wide variety of phthalates were researched of which only two were present in significant amounts. Mean concentrations of di-(2-ethylhexyl) phthalate (DEHP) and diethyl phthalate (DEP) measured throughout the system were 23.6 and 25.0 microg/l in raw sewage, 22.0 and 24.8 microg/l in primary, 14.6 and 0.60 microg/l in trickle filter, 18.6 and 0.10 microg/l in humus tank and 18.5 and 0.40 microg/l in reedbed effluents, respectively. Removal by the trickle filter was constantly high for DEP (94-99%) whereas DEHP was variable (<1-44%). Mean concentrations of DEHP and DEP in raw sludge were 30.2 and 1.60 microg/g dry wt, respectively. A mass balance for DEHP was calculated using data from field studies and estimates of sludge production at the works. The mass balance approach helped to provide information that could be used to improve the design and operation of sewage treatment works.     

Three-dimensional non-isothermal numerical model for predicting semi-volatile organic compound transport process in a room

In this paper, a three-dimensional non-isothermal computational model for predicting indoor SVOC distribution is proposed, considering the effects of turbulence diffusion and suspended particles. The realizable k-ε model is introduced for turbulent flow simulation in a room. The Euler-Euler method is adopted to deal with the gas-particle two-phase flow coupled problem. Inertia slip velocity and irreversible first-order absorption boundary are employed for more accurate prediction of particle motion. The simulated curve of outlet gas-phase di-2-ethylhexyl phthalate (DEHP) concentration with emission time is verified by available experimental data. The emission process of DEHP in a 15 m² room in Beijing during 100 days with or without air cleaner is simulated by the developed model considering air leak through window and door gaps. It is found that if the air cleaner keeps on all the time during 100 days the gas-phase DEHP concentration in the room will tend to be uniform, while the emission process is far from equilibrium without an air cleaner even the emission lasts 100 days. Results also suggest that floor heating, decrease of particle concentration, weaken of heat transfer, enhancement of mass transfer, and air infiltration in window gap contribute to decrease DEHP concentration.     

Semi‐volatile organic compounds in heating,ventilation, and air‐conditioning filter dust in retail stores

Retail stores contain a wide range of products that can emit a variety of indoor pollutants. Among these chemicals, phthalate esters and polybrominated diphenyl ethers (PBDEs) are two important categories of semi‐volatile organic compounds (SVOCs). Filters in heating, ventilation, and air‐conditioning (HVAC) system collect particles from large volumes of air and thus potentially provide spatially and temporally integrated SVOC concentrations. This study measured six phthalate and 14 PBDE compounds in HVAC filter dust in 14 retail stores in Texas and Pennsylvania, United States. Phthalates and PBDEs were widely found in the HVAC filter dust in retail environment, indicating that they are ubiquitous indoor pollutants. The potential co‐occurrence of phthalates and PBDEs was not strong, suggesting that their indoor sources are diverse. The levels of phthalates and PBDEs measured in HVAC filter dust are comparable to concentrations found in previous investigations of settled dust in residential buildings. Significant correlations between indoor air and filter dust concentrations were found for diethyl phthalate, di‐n‐butyl phthalate, and benzyl butyl phthalate. Reasonable agreement between measurements and an equilibrium model to describe SVOC partitioning between dust and gas‐phase is achieved.     

Application of ozone, UV and ozone/UV processes to reduce diethyl phthalate and its estrogenic activity

A research study to monitor the micropollutant levels present in the Han River, a major drinking water source for the Seoul Metropolitan district in Korea, was performed over a five-year period from 2000 to 2004, inclusive. Of the detected micropollutants, phthalates were found to be the major contaminants. In this study, the estrogenic activities of the detected phthalates and raw water samples contaminated with the pollutants were assessed by the E-screen assay using the MCF-7 breast cancer cell line. Of the phthalates, diethyl phthalate (DEP) and di(2-ethylhexyl) phthalate (DEHP) showed relatively high cell proliferation. Using DEP as a phthalate probe, three candidate processes, ozone alone, UV alone, and the ozone/UV combined, were evaluated for their efficiency in removing DEP and reducing its estrogenic activity. The ozone/UV process was shown to have the highest efficiency for the elimination of DEP and its by-products, leading to the complete mineralization of DEP. This study also found that the ozone/UV process is the best candidate to reduce the estrogenicity induced by DEP and its by-products.     

Occurrence of phthalates and musk fragrances in indoor air and dust from apartments and kindergartens in Berlin (Germany)

In this study, the occurrence of persistent environmental contaminants room air samples from 59 apartments and 74 kindergartens in Berlin were tested in 2000 and 2001 for the presence of phthalates and musk fragrances (polycyclic musks in particular). These substances were also measured in household dust from 30 apartments. The aim of the study was to measure exposure levels in typical central borough apartments, kindergartens and estimate their effects on health. Of phthalates, dibutyl phthalate had the highest concentrations in room air, with median values of 1083 ng/m(3) in apartments and 1188 ng/m(3) in kindergartens. With around 80% of all values, the main phthalate in house dust was diethylhexyl phthalate, with median values of 703 mg/kg (range: 231-1763 mg/kg). No statistically significant correlation could be found between air and dust concentration. Musk compounds were detected in the indoor air of kindergartens with median values of 101 ng/m(3) [1,3,4,6,7,8-hexahydro-4,6,6,7,8,8- hexamethylcyclopenta-(g) 2-benzopyrane (HHCB)] and 44 ng/m(3) [7-acetyl-1,1,3,4,4,6-hexamethyl-tetraline (AHTN)] and maximum concentrations of up to 299 and 107 ng/m(3) respectively. In household dust HHCB and AHTN were detected in 63 and 83% of the samples with median values of 0.7 and 0.9 mg/kg (Maximum: 11.4 and 3.1 mg/kg) each. On comparing the above phthalate concentrations with presently acceptable tolerable daily intake values (TDI), we are talking about only a small average intake [di(2-ethylhexyl) phthalate and diethyl phthalate less than 1 and 8% of the TDI] by indoor air for children. The dominant intake path was the ingestion of foodstuffs. For certain subsets of the population, notably premature infants (through migration from soft polyvinyl chloride products), children and other patients undergoing medical treatment like dialysis, exchange transfusion, an important additional intake of phthalates must taken into account. PRACTICAL IMPLICATIONS: The phthalate and musk compounds load in a sample of apartments and kindergartens were low with a typical distribution pattern in air and household dust, but without a significant correlation between air and dust concentration. The largest source of general population exposure to phthalates is dietary. For certain subsets of the general population non-dietary ingestion (medical and occupational) is important.     

Study on emission of decomposed chemicals of esters contained in PVC flooring and adhesive

2-Ethyl-1-hexanol (2E1H) is sometimes detected in indoor air at relatively high concentrations. The emission mechanism for 2E1H is considered to be that moisture with a high pH in concrete slabs and self-leveling sub-flooring material reacts with di-2-ethylhexyl phthalate (DEHP) in the polyvinyl chloride (PVC) flooring and compounds containing the 2-ethyl-1-hexyl group in the adhesive. 2E1H is considered to be one of the causes of odor in indoor air and sick building syndrome, so it is important to clarify the 2E1H emission mechanism for IAQ. However, there are few reports on any experimentation into 2E1H emission by chemical reaction involving building materials. In this study, PVC floorings are attached using various adhesives to a self-leveling sub-flooring material that contains water, and their 2E1H emission rates are measured. Furthermore, the components of the adhesives are determined using chemical analysis. It is found that 2E1H emission rates from the floor are affected by the type of adhesive used. On the other hand, some components in the adhesives may suppress the hydrolysis of esters. The hydrolysis of polymers and residual monomers in the adhesive causes 2E1H emission from the adhesive.