Presentation on theme: "Health Hazards of Solvents James E. Cone MD, MPH and Karen Packard, RDH, MS This presentation is made possible by a grant from the Association of Occupational."— Presentation transcript:
Health Hazards of Solvents James E. Cone MD, MPH and Karen Packard, RDH, MS This presentation is made possible by a grant from the Association of Occupational and Environmental Clinics and the National Institute for Occupational Safety & Health.
Module Goals n To provide an overview of occupational solvent exposure n To review potential health outcomes and public health prevention options. n To provide step by step approach to diagnostic testing and treatment of solvent- related diseases n To provide background information on specific solvents n To illustrate the diverse effects of solvents through cases involving solvent toxicity
What is a solvent? Classes of Common Organic Solvents: aliphatic hydrocarbons amines cyclic hydrocarbons esters aromatic hydrocarbons alcohols halogenated hydrocarbons ketones aldehydes ethers A solvent is a liquid at room temperature used to dissolve other substances Permission to use photo requested from AIHA Lab Safety Committee
Scope of the Problem n Over 49 million tons of solvent chemicals are produced and used each year in the US alone. n Often exposure involves a mixture of solvents. Permission requested from US Navy
Occupational Disease due to Solvents? n 390,000 new cases of all types of occupational disease appear annually in the US. n It is unknown how many of these cases may be related to solvent exposure. n Similar to other occupational diseases, 95% of all occupational solvent-related disease cases are never reported, most are never recognized as being occupationally-related.
Occupational Environmental n Workplace solvents may also result in exposures to neighborhood residents if discharged from workplaces without adequate controls. Other hazards: –Fire or explosion –Improper storage or disposal Used with Permission of
Occupational Environmental n Residual perchloroethylene solvent may be present in freshly dry cleaned clothes
Properties of Solvents n Solubility n Non-flammability/ Flammability/ Explosivity n Volatility n Metabolism n Complex mixtures Used with permission of Advanced Chemistry Development Co. Graphic
Routes of Solvent Exposure n Inhalation n Absorption -skin -mucous membranes n Ingestion n Injection Jane Norling Graphic
Biological Monitoring For Example: n Urine testing for: –Benzene Phenol –Toluene Hippuric Acid, o-Cresol –Xylene Methyl Hippuric Acid –n-Hexane 2,5 hexanedione* -References: ACGIH Biological Exposure Indices * Not commercially available at this time Corel Graphic
Occupations Exposed to Solvents n Painters n Construction workers n Semiconductor workers n Machinists / auto mechanics n Manufacturing workers –Glue, Paint, Chemical, Plastics –Rotogravure Printers, Metal Degreasers n Graffiti removers n Refinery workers n Manicurists n Drycleaners n Many others
Solvent Related Diseases n Acute Intoxication n Chemical Headache n Chemical Hepatitis n Chronic Toxic Encephalopathy n Hematological Effects n Renal Effects n Reproductive Health Effects n Toxic Peripheral Neuropathy Bill Bowerman developed n-Hexane related peripheral neuropathy from glues used for running shoes
Dx of Solvent-Related Disease n 10 Step Process n Certain conditions should trigger the thought that it might be solvent-related : –Chemical hepatitis, peripheral neuropathy, chronic headache, chronic cognitive impairment, miscarriage, and asthma. Corel Graphic
Dx: Step 1 - Medical & Exposure Records n Prior medical records n Industrial Hygiene data n Labels, Material Safety Data Sheets (MSDS), Chemical Inventory Lists n OSHA reports
Dx: Step 2 - Exposure History n Symptoms & Exposure History n Complete History & Physical Examination n Specific job duties, solvent exposures n Exposure monitoring n Frequency of acute solvent intoxication episodes
Acute Solvent Intoxication -Stages n Narcosis impaired psychomotor function as measured by reaction time, manual dexterity, coordination, or body balance n Anesthesia n Central nervous system depression n Respiratory arrest n Unconsciousness
Dx: Step 3 - Medical History n Asthma n History of Blood Dyscrasias n Hearing loss n History of Psychological Problems –Prior to exposure –After exposure
Dx: Step 4 - Physical Examination Focus on: n Skin n Eyes n Gastro - intestinal n Neurologic system n Mental Status
Dx: Step 5 - Laboratory Tests n Screening n Biological Indices n Pathologic Indices NIOSH Database of Medical Tests for OSHA Regulated Substances: http://www.cdc.gov/niosh/nmed/medstart.html Corel Graphic
Dx: Step 6 - Other Testing n Nerve Conduction Studies n Color Vision n Hearing n Pontogram (blink reflex – facial and trigeminal nerve evaluation) n Peak flow
Dx: Step 7 - Site Visit “Walk Through” of Patient’s Workplace n Assess workplace and potential exposures –Personal or area industrial hygiene sampling –Ventilation of worksite –Potential skin exposure n Obtain prior environmental test results, if available
Dx: Step 8 - Relationship? n Decide whether the the patient’s diagnosis is more likely than not work-related. n Is the latency period adequate? n Exposure data consistent?
Dx: Step 9 - Make the Diagnosis n Was the dose of the solvent exposure adequate, in your opinion, to cause the problem? (e.g., is there a history of acute intoxication episodes?) n OR Is patient particularly sensitive to the effects of solvents (e.g. increased individual susceptibility or acquired intolerance)?
Dx: Step 9 - Diagnosis n Rule out other diseases with similar outcomes: –e.g., Alcoholic Hepatitis/ Hepatitis B n Decide if a pre-existing condition exists that has been exacerbated. n File Clinician’s First Report, if required by State Law.
Dx: Step 10 - Disposition n Return to work n Modified duty / preclusions n Factors of disability –Objective/ Subjective n Vocational rehabilitation n Apportionment n Future medical care
Prevention of Solvent Exposures n Elimination n Substitution n Engineering Controls n Administrative Controls – Isolation n Personal Protective Equipment n Education Used with permission from
Personal Protective Equipment n Protective Clothing-Impermeable aprons n Gloves – Breakthrough time depends on type of glove, solvent exposure and activity. n Chemically resistant gloves: natural rubber, butyl rubber, chloroprene, nitrile, and fluorocarbon; or various plastics: polyvinyl chloride, polyvinyl alcohol, polyethylene Permission requested from
Personal Protective Equipment- Respirators Respirator Program must include: n Training n Cleaning n Fit testing n Medical Clearance n Change of filters –schedule depends on exposure type and amount
Environmental pressures are often the primary cause of solvent substitution. n Montreal Protocol n Clean Air Act n Pollution Prevention (P2)
Additional Resources n Handouts n Bibliography n Web Sites –Jonathan S Rutchik, MD, MPH Organic Solvents http://www.emedicine.com/neuro/topic285.htmJonathan S Rutchik, MD, MPH n Acknowledgements: –Photos by Janet Delaney –Elizabeth Katz, MPH, CIH –Rosemarie Bowler, PhD –Public Health Institute, AOEC and NIOSH staff