Neurological Effects of White Spirit: Contribution of Animal Studies during a 30-Year Period*

Occupational co-exposure to biomechanical factors and neurotoxic chemicals in a representative sample of French employees

Objectives

Musculoskeletal disorders, mainly carpal tunnel syndrome, represent a leading cause of compensation claims of workers worldwide. Despite this, and the fact that occupational exposures to biomechanical factors and neurotoxic chemicals have been individually associated with peripheral nerve damage, the prevalence of occupational co‐exposure to biomechanical factors and neurotoxic chemicals has rarely been explored. Therefore, our aim was to assess the prevalence of occupational co‐exposure to biomechanical factors and neurotoxic chemicals in a national representative sample of the French working population.

Methods

The study was based on the French representative cross‐sectional survey SUMER 2010. A total of 47 983 employees who had worked in their current job for at least one year were included. Occupational exposure to biomechanical factors and neurotoxic chemicals within the previous week of work were assessed using a questionnaire during face‐to‐face interviews with occupational physicians.

Results

Approximately 5% of male employees and 1% of female employees were co‐exposed to biomechanical factors and neurotoxic chemicals. This prevalence was up to 10% among male blue‐collar workers and 13%, 8%, and 6%, respectively, among male employees in the construction, agriculture, and industry sectors. Male employees under 30 years old, in apprenticeships, and working in small companies were more co‐exposed to biomechanical factors and neurotoxic chemicals than their counterparts.

Conclusions

Occupational co‐exposure to biomechanical factors and neurotoxic chemicals was observed in a significant proportion of French male employees, suggesting that further studies are required to investigate its potential adverse effects on peripheral neuropathies.

Assessment of the potential human health risks from exposure to complex substances in accordance with REACH requirements. "White spirit" as a case study

The European chemical control regulation (REACH) requires that data on physical/chemical, toxicological and environmental hazards be compiled. Additionally, REACH requires formal assessments to ensure that substances can be safely used for their intended purposes. For health hazard assessments, reference values (Derived No Effect levels, DNELs) are calculated from toxicology data and compared to estimated exposure levels. If the ratio of the predicted exposure level to the DNEL, i.e. the Risk Characterization Ratio (RCR), is less than 1, the risk is considered controlled; otherwise, additional Risk Management Measures (RMM) must be applied. These requirements pose particular challenges for complex substances. Herein, "white spirit", a complex hydrocarbon solvent, is used as an example to illustrate how these procedures were applied. Hydrocarbon solvents were divided into categories of similar substances. Representative substances were identified for DNEL determinations. Adjustment factors were applied to the no effect levels to calculate the DNELs. Exposure assessments utilized a standardized set of generic exposure scenarios (GES) which incorporated exposure predictions for solvent handling activities. Computer-based tools were developed to automate RCR calculations and identify appropriate RMMs, allowing consistent communications to users via safety data sheets.

Neurotoxicity of solvents

Worldwide, several hundred million tons of organic solvents are used annually in household, industry, and other occupational settings. Millions of workers are regularly exposed to organic solvents considered neurotoxic. Acute neurotoxicity due to high exposure of solvent is usually evident, but the nature of long-term effects, such as chronic solvent encephalopathy (CSE), has raised uncertainty even among experts. Earlier studies were criticized for their methodology, mainly epidemiologic studies or investigations of exposed groups with many possible confounders and inadequate exposure assessment. However, an increasing number of studies have been performed since, also on workers with defined CSE based on differential diagnostics. During the last decade, evidence has emerged to enable identification of CSE, a necessity for the early recognition and prevention of progression of dysfunction and disability. Selected chemicals are presented here due to their widespread use, neurotoxic potential, and ability to cause solvent encephalopathy. Constant introduction of new chemicals may introduce new hazardous chemicals or known chemicals may reveal new health effects. It is important to keep an open mind for new findings of solvent-related neurobehavioral effects.

Chronic solvent-induced encephalopathy: European consensus of neuropsychological characteristics, assessment, and guidelines for diagnostics

INTRODUCTION

The presence of neuropsychological impairment is a hallmark of chronic solvent-induced encephalopathy (CSE), and using clinical neuropsychological procedures to generate a valid assessment of the condition is crucial for its diagnosis. The goals of this consensus document are to provide updated knowledge of the neuropsychological characteristics of CSE and to provide internationally acceptable guidelines for using neuropsychological assessments in the process of diagnosing patients who are suspected of having CSE.

MATERIALS AND METHODS

A European working group that was composed of experts in the field of the clinical diagnosis of CSE met at several round-table meetings and prepared this report. The first section of the consensus paper addresses a review of the relevant literature that was published between 1985 and March 2012. The second section addresses recommendations for the clinical neuropsychological assessment of patients who are suspected of having CSE.

RESULTS

The literature review indicates that the most common neuropsychological impairments in CSE patients are within the domains of attention, particularly the speed of information processing, memory, and motor performance. It appears that the influence of CSE on memory processes mainly involves immediate recall and generally involves verbal, visual and visuospatial material. In the second section, six recommendations are presented regarding important functional domains for the neuropsychological diagnostic process of CSE that relate to the evaluation of neuropsychological impairment, the assessment and evaluation of symptoms, differential diagnostic considerations, the reliability and validity of neuropsychological test results, and the retesting of patients.

DISCUSSION AND CONCLUSIONS

These recommendations will contribute to the improvement of the process for accurately diagnosing CSE, better counselling for CSE patients, the comparability of epidemiological data between countries, and finally, by raising awareness, these recommendations will contribute to combating the adverse health effects of occupational exposure to solvents.

Chemical Burns and Multiorgan Failure following Acute Ingestion of White Spirit: A Case Report and Review of the Literature

Organic solvents are chemically different compounds with one common feature: they dissolve fats, oils and resins, which makes them widely used in industry. Organic solvents are used in paint and lacquer industries, in the production of pesticides, plastics, explosives and in the pharmaceutical industry. The most common household solvent is white spirit, used as a paint remover. We report a case of acute white spirit ingestion causing multiorgan failure and a prolonged intensive care unit admission. Such a case has not been documented previously and highlights a number of diagnostic and therapeutic considerations. The patient also represents the first reported case of chemical burns from erosive diarrhoea secondary to white spirit ingestion.