Emissions of two phthalate esters and BDE 209 to indoor air and their impact on urban air quality.

Estimated emissions of decabrominated diphenyl ether (BDE 209) and the two phthalate esters diethylhexyl phthalate (DEHP) and diisononyl phthalate (DINP) to indoor air in the Stockholm conurbation, Sweden were used to assess the contribution of chemical outflows from the indoor environment to urban outdoor air pollution for these substances, by applying the recently developed Stockholm MUltimedia URban fate (SMURF) model. Emission rates of DINP from PVC materials were measured and published emission rates of DEHP were adapted to Swedish conditions. These were used as input to the model, as well as recently reported estimates of BDE 209 emissions to indoor air in Stockholm. Model predicted concentrations were compared to empirical monitoring data obtained from the literature and from additional measurements of phthalates in ventilation outlets and urban air performed in the current study. The predicted concentrations of the phthalates DINP and DEHP in indoor air and dust were within a factor of 1.5-10 of the measured concentrations. For BDE 209, predicted indoor concentrations were within the measured ranges, but measured concentrations showed a much larger variability. An adjusted emission scenario to better fit observed concentrations indoors was employed for DEHP and final outcomes resulted in estimated indoor emissions of 250 (50-1250), 2.9 (0.58-15), and 0.068 (0.014-0.34) kg year(-1) for DEHP, DINP and BDE 209. These emissions could not explain the observed concentrations in urban air of the phthalates, suggesting an underestimation of background inflow or existence of additional sources in the outdoor environment. For BDE 209, the assessment indicates that the Stockholm indoor environment contributes about 25% to the air pollution load in inflowing background air, but additional monitoring data in urban air are needed to confirm this conclusion.

A generic emission model to predict release of organic substances from materials in consumer goods.

Organic chemicals may be released when consumer goods are used, contributing to environmental and human levels of potentially hazardous chemicals. A generic model was developed to predict emissions of organic chemicals from various materials in consumer products. The model involved three modules, which each predict a key parameter needed to calculate the mass of individual chemicals emitted. Partition coefficients between a material and the surrounding air were predicted using Abraham solvation parameters, diffusion coefficients in materials were calculated using the Piringer equation, and convective mass transfer coefficients were evaluated by applying the Chilton-Colburn analogy. The calculated emission rates from predicted parameters were evaluated and agreed well with literature data. The release of plasticizers from vinyl flooring used in Sweden was calculated to demonstrate the utility of the generic model. The estimated emitted masses of di(2-ethylhexyl)phthalate (DEHP), di-iso-nonylphthalate (DINP), and 1,2-cyclohexanedicarboxylic acid di-iso-nonyl ester (DINCH) in 2012 were 210 kg, 40 kg, and 3.6 kg respectively. Emissions from vinyl flooring were estimated for the period 1990 to 2035 and it was shown that the recent substitution of DEHP with DINP will help to reduce plasticizer emissions. Model calculations for alternative plasticizers revealed that DINCH would yield similar emissions to DINP, whereas use of diethyl hexyl-iso-sorbide or diethyl hexyl adipate would result in higher emissions.