Health risk assessment of exposures to a high molecular weight plasticizer present in automobile interiors.

This study provides an exposure and risk assessment of diundecyl phthalate (DUP), a high molecular weight phthalate plasticizer present in automobile interiors. Total daily intake of DUP was calculated from DUP measured in wipe samples from vehicle seats from six automobiles. Four of the vehicles exhibited atypical visible surface residue on the seats. Two vehicles with no visible surface residue were sampled as a comparison. DUP was the predominant organic compound identified in each of the wipes from all seats. A risk assessment of DUP via oral, dermal, and inhalation routes resulting from contact with automobile seats was conducted. The mean, standard deviation, and maximum DUP concentrations on the seats with visible surface residue were 6983 ± 7823 µg/100 cm2 and 38300 µg/100 cm2, respectively. The mean and 95th percentile of the mean for daily cumulative dose of DUP for all exposure routes for the seats with no visible surface residue ranged from 7 × 10-4 to 4 × 10-3 mg/kg-day and from 8 × 10-4 to 5 × 10-3 mg/kg-day, respectively. For seats with visible surface residue, cumulative doses ranged from 2 × 10-3 to 2 × 10-2 mg/kg-day and from 4 × 10-3 to 2 × 10-2 mg/kg-day, respectively. The estimated daily intake (contact or absorbed dose) of DUP from automobile seats were far lower than the NOAELs reported in and derived from animal studies, and are well below the reported Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Derived No Effect Levels (DNELs) for the general population. Based on this analysis, using virtually any benchmark for evaluating safety, exposure to DUP via automobile seat covers did not pose a measureable increased health-risk in any population under any reasonably plausible exposure scenario.

The healthy workplace project: Reduced viral exposure in an office setting.

Viral illnesses such as gastroenteritis and the common cold create a substantial burden in the workplace due to reduced productivity, increased absenteeism, and increased health care costs. Behaviors in the workplace contribute to the spread of human viruses via direct contact between hands, contaminated surfaces, and the mouth, eyes, and/or nose. This study assessed whether implementation of the Healthy Workplace Project (HWP) (providing hand sanitizers, disinfecting wipes, facial tissues, and use instructions) would reduce viral loads in an office setting of approximately 80 employees after seeding fomites and the hands of volunteer participants with an MS-2 phage tracer. The HWP significantly reduced viable phage detected on participants' hands, communal fomites, and personal fomites (p ≤ .010) in office environments and presents a cost-effective method for reducing the health and economic burden associated with viral illnesses in the workplace.

Modeling of human viruses on hands and risk of infection in an office workplace using micro-activity data.

Although the number of illnesses resulting from indirect viral pathogen transmission could be substantial, it is difficult to estimate the relative risks because of the wide variation and uncertainty in human behavior, variable viral concentrations on fomites, and other exposure factors. The purpose of this study was to evaluate the micro-activity approach for assessment of microbial risk by adapting a mathematical model to estimate probability of viral infection from indirect transmission. To evaluate the model, measurements of phage loading on fomites and hands collected before and after implementation of a Healthy Workplace Project intervention were used. Parameter distributions were developed from these data, as well as for micro-activity rates, contact surface areas, phage transfer efficiencies, and inactivation rates. Following the Monte Carlo simulations (n = 1,000), the estimated phage loading on hands was not significantly different from the loading of phage on hands measured in the experimental trials. The model was then used to demonstrate that the Healthy Workplace Project intervention significantly reduced risk of infection by 77% for rotavirus and rhinovirus. This is the first published study to successfully evaluate a model focused on the indirect transmission of viruses via hand contact with measured data and provide an assessment of the micro-activity approach to microbial risk evaluation.