A control banding method for chemical risk assessment in occupational settings in France.

Background: This study describes a method whose aim is to help companies assess the chemical occupational risks related to labeled products and industrial chemical emissions. The method is intended to be used by industrial hygienists at the scale of one company. Both inhalation and cutaneous exposure routes are taken into account. Methods: The method relies on a control-banding scheme. A work situation is described by exposure parameters such as the process or the local exhaust ventilation and by the hazard of the product. Each possible value of the parameters is associated with a "band," which is associated with an integer value. The multiplication of these values results in a score, which represents a priority for intervention. The higher the score, the more the situation warrants investigation for implementing prevention measures, such as chemical substitution and the addition of local exhaust ventilation. To simplify communication, the priority is associated with a colored priority band: red for "very high priority," orange for "high priority," and green for "moderate priority." The priority bands are computed for all work situations performed in a company. Results: An example of the use of this method is described in a French façade insulation company. Conclusion: A tool named Seirich was developed to implement this method and promote good practices for helping industrial hygienists in the prioritization of interventions for reducing chemical risk in France.

Chemical-by-chemical and cumulative risk assessment of residential indoor exposure to semivolatile organic compounds in France.

BACKGROUND: The toxic effects of environmental exposure to chemicals are increasingly being studied and confirmed, notably for semivolatile organic compounds (SVOCs). These are found in many products and housing materials, from which they are emitted to indoor air, settled dust and other surfaces. OBJECTIVES: The objective of this work is to assess the human health risk posed by residential indoor exposure to 32 SVOCs, assessed in previous nationwide studies. METHODS: A chemical-by-chemical risk assessment, using a hazard quotient (HQ) or excess risk (ER) method, was supplemented by a cumulative risk assessment (CRA). For CRA, a hazard index (HI) method, as well as higher tier approaches using relative potency factors (RPFs) or toxic equivalency factors (TEFs) were used for the following endpoints: neurotoxicity, reproductive toxicity, genotoxicity and immunotoxicity. RESULTS: HQs were above 1 for 50% of French children from birth to 2 years for BDE 47, and for 5% of children for lindane and dibutyl phthalate (DBP). Corresponding hazards are reprotoxic for BDE 47 and DBP, and immunotoxic for lindane. The CRA approach provided additional information of reprotoxic risks (HI > 1) that may occur for 95% of children and for 5% of the offspring for pregnant women's exposure. The SVOCs contributing most to these risks were PCB 101 and 118, BDE 47, and DBP. The higher tier CRA approaches showed that exposure to dwellings' SVOC mixtures were of concern for 95% of children for neurotoxic compounds having effects linked with neuronal death. To a lesser extent, effects mediated by the aryl hydrocarbon receptor (AhR) or by a decrease in testosterone levels may concern 5% of children and adults. Lastly, unacceptable immunotoxic risk related to exposure to 8 indoor PCBs was also observed for 5% of children. CONCLUSIONS: In view of uncertainties related to compounds' toxicity for humans, these results justify the implementation of preventive measures, as well as the production of more standardized and comprehensive toxicological data for some compounds.

Dermal absorption of semivolatile organic compounds from the gas phase: Sensitivity of exposure assessment by steady state modeling to key parameters.

Recent research has demonstrated the importance of dermal exposure for some semivolatile organic compounds (SVOCs) present in the gas phase of indoor air. Though models for estimating dermal intake from gaseous SVOCs exist, their predictions can be subject to variations in input parameters, which can lead to large variation in exposure estimations. In this sensitivity analysis for a steady state model, we aimed to assess these variations and their determinants using probabilistic Monte Carlo sampling for 8 SVOCs from different chemical families: phthalates, bisphenols, polycyclic aromatic hydrocarbons (PAHs), organophosphorus (OPs), organochlorines (OCs), synthetic musks, polychlorinated biphenyls (PCBs) and polybromodiphenylethers (PBDEs). Indoor SVOC concentrations were found to be the most influential parameters. Both Henry's law constant (H) and octanol/water partition coefficient (Kow) uncertainty also had significant influence. While exposure media properties such as volume fraction of organic matter in the particle phase (fom-part), particle density (ρpart), concentration ([TSP]) and transport coefficient (É£d) had a slight influence for some compounds, human parameters such as body weight (W), body surface area (A) and daily exposure (t) make a marginal or null contribution to the variance of dermal intake for a given age group. Inclusion of a parameter sensitivity analysis appears essential to reporting uncertainties in dermal exposure assessment.

An exposure-based framework for grouping pollutants for a cumulative risk assessment approach: case study of indoor semi-volatile organic compounds.

Humans are exposed to a large number of contaminants, many of which may have similar health effects. This paper presents a framework for identifying pollutants to be included in a cumulative risk assessment approach. To account for the possibility of simultaneous exposure to chemicals with common toxic modes of action, the first step of the traditional risk assessment process, i.e. hazard identification, is structured in three sub-steps: (1a) Identification of pollutants people are exposed to, (1b) identification of effects and mechanisms of action of these pollutants, (1c) grouping of pollutants according to similarity of their mechanism of action and health effects. Based on this exposure-based grouping we can derive "multi-pollutant" toxicity reference values, in the "dose-response assessment" step. The approach proposed in this work is original in that it is based on real exposures instead of a limited number of pollutants from a unique chemical family, as traditionally performed. This framework is illustrated by the case study of semi-volatile organic compounds in French dwellings, providing insights into practical considerations regarding the accuracy of the available toxicological information. This case study illustrates the value of the exposure-based approach as opposed to the traditional cumulative framework, in which chemicals with similar health effects were not always included in the same chemical class.

Urinary biomarkers of exposure to glycol ethers and chlorinated solvents during pregnancy: determinants of exposure and comparison with indirect methods of exposure assessment.

OBJECTIVES: To describe urine levels of metabolites of glycol ethers and chlorinated solvents in a sample of pregnant women from the general population, to study their occupational and non-occupational determinants and to compare them with the results of indirect assessment methods of solvent exposure. METHODS: A sample of 451 pregnant women was randomly selected from a general population cohort. At inclusion, the women in this sample completed a self-administered questionnaire about their social and medical characteristics, occupation and exposure to different products at work and in non-occupational activities. Occupational exposure to solvents was assessed from the woman's self-report and from a job-exposure matrix. Eight alkoxycarboxylic acids and trichloroacetic acid and trichloroethanol were measured with chromatography in urine samples collected at inclusion. Associations between metabolite levels and job titles, exposure to products used at work, and solvent exposure were studied. RESULTS: The different glycol ether metabolites were detected in 5.3%-96.4% of the urine samples, trichloroacetic acid in 6.4% and trichloroethanol in 5.5%. Nurses had butoxyacetic acid and phenoxyacetic acid in their urine most often, whereas methoxyethoxyacetic acid was the most frequent among nursing aides. Among cleaners, ethoxyacetic acid and ethoxyethoxyacetic acid were the most frequent. The occupation of hairdresser was associated with urinary excretion of ethoxyacetic acid, ethoxyethoxyacetic acid, butoxyacetic acid and phenoxyacetic acid. Among the women classified as exposed to solvents, the agents identified most often were ethoxyacetic acid, ethoxy-ethoxyacetic acid, butoxyacetic acid, phenoxyacetic acid, trichloroacetic acid and trichloroethanol. Ethoxyethoxyacetic acid was the only metabolite associated with non-occupational exposure. CONCLUSIONS: Metabolites of glycol ethers and chlorinated solvents were present at low levels in the urine of pregnant women. Most metabolites were associated with occupational exposure.

Indoor environment and children's health: recent developments in chemical, biological, physical and social aspects.

Much research is being carried out into indoor exposure to harmful agents. This review focused on the impact on children's health, taking a broad approach to the indoor environment and including chemical, microbial, physical and social aspects. Papers published from 2006 onwards were reviewed, with regards to scientific context. Most of publications dealt with chemical exposure. Apart from the ongoing issue of combustion by-products, most of these papers concerned semi volatile organic compounds (such as phthalates). These may be associated with neurotoxic, reprotoxic or respiratory effects and may, therefore, be of particular interest so far as children are concerned. In a lesser extent, volatile organic compounds (such as aldehydes) that have mainly respiratory effects are still studied. Assessing exposure to metals is still of concern, with increasing interest in bioaccessibility. Most of the papers on microbial exposure focused on respiratory tract infections, especially asthma linked to allergens and bio-aerosols. Physical exposure includes noise and electromagnetic fields, and articles dealt with the auditory and non auditory effects of noise. Articles on radiofrequency electromagnetic fields mainly concerned questions about non-thermal effects and papers on extremely low-frequency magnetic fields focused on the characterization of exposure. The impact of the indoor environment on children's health cannot be assessed merely by considering the effect of these different types of exposure: this review highlights new findings and also discusses the interactions between agents in indoor environments and also with social aspects.

Haber's rule duration adjustments should not be used systematically for risk assessment in public health decision-making.

Human health risk assessment can be used to support decisions for public health regulations and actions. Characterizing the hazards of inhaled toxicants generally includes extrapolation from observations on experimental animals, subjected to intermittent or subchronic exposures, to a human environmental context with exposure that is usually continuous and long-term. The extrapolation is usually based on a simple linear relationship derived from Haber's rule which assumes that, for a given chemical compound, multiplying the same concentration by the same duration of exposure will yield the same biological response. This study assessed the reliability of this assumption. The p-power in the equation C×t(p)=k was calculated for 21 chemicals, based on a comparison of LOAELs for subacute, subchronic and chronic durations. A bibliographic survey was then carried out to study the reliability of the intermittent-to-continuous exposure adjustment factors currently used in risk assessment. The results showed that the value of p, assumed to be 1 in risk assessment methodology, was not in fact equal to 1 for any of the selected chemicals. Moreover, in the case of respiratory tract irritation, the value of p varied from 0 to 0.44, as confirmed by experimental studies. These results suggest that a more in-depth and case-by-case approach is required for regulatory toxicology, based on toxicokinetics and toxicodynamic data analysis for each toxicant before applying a temporal-adjustment factor.