Health Hazards of SolventsCase Studies

James E. Cone MD, MPH

and Karen Packard, RDH, MSThis presentation is made possible by a grant from the Association of Occupational and Environmental Clinics

and the National Institute for Occupational Safety & Health.

Acknowledgements

Elizabeth Katz, MPH, Industrial Hygienist, Occupational Health Branch, California Department of Health Services

Robert Harrison, MD, MPH, UCSF Occupational Medicine Clinic

Karen Packard, Health Educator Janet Delaney, Photographer Specific photo acknowledgements are listed

on slides

Case 1: Auto Mechanic 24 y.o. male

Auto Mechanic

Worked for 22 months

October 1996: fatigue

January 1997 : – Swollen hands– Numbness, tingling both

hands and plantar surfaces of both feet

– Spread to legs, waist and lower forearms

Other workers reported similar symptoms, less severe

Photo used with permission: A. Chandrasekhar, Loyola University

Exposure History Auto Mechanic: Brake repair

Top worker for 10 months

(# jobs/day)

Medical History

No prior history of diabetes or thyroid disease

Alcohol: One drink per week.

Exposure History: Amount Used 5-10 12-oz. aerosol cans / day of same

brake cleaner

Frequently sprayed on rag, latex gloves used

No local ventilation but had open garage doors, except in winter

No IH or biological monitoring in past

No hobbies with solvent exposure

Previous use of perchloroethylene mixtures

Specific Solvent 50-60% hexane

(composed of 20-80% n-hexane)

20-30% toluene 1-10% each of methyl

ethyl ketone, acetone, isopropanol, methanol & mixed xylenes.

MSDS for Brake Cleaner

Physical Exam No skin changes

HEENT: – No nystagmus– Visual acuity normal– No loss of smell– No loss of hearing

GI: Liver size 8mm to percussion

Photo used with permission: A. Chandrasekhar, Loyola University

Neurological Exam

Marked sensory deficits with complete loss of joint position sense in lower extremities

Romberg test – positive

Abnormal tandem gait

Deep tendon reflexes absent bilaterally in all extremities

Photo used with permission: A. Chandrasekhar, Loyola University

Mental Status

Normal serial 7’s

Recalls 3 objects at 5 minutes

Digit span 10 forward, 6 reverse

Photo used with permission A. Chandrasekhar, Loyola University

Diagnostic Tests, Rx, Referral Liver Function: AST 33 U/L (Normal 0-35

U/L), ALT 50 (Normal 0-35 U/L).

No biological monitoring was performed as he had been removed from further exposure. – What biological monitoring could have been

performed if he was continuing to work with solvents?

– Nerve Conduction Tests– Abnormal, subacute progressive mixed motor -

sensory neuropathy with predominant distal nerve involvement

Initial Diagnosis: Guillain-Barre Syndrome Treatment: Trial of steroids Referral: Occupational Medicine Consultation

Biological MonitoringSubstance TLV Skin Abs. BEI Urine/l

Hexane 50 Yes 2,5hexanedione

5 mg/g creat.

Toluene 50 Yes O-cresol 0.5 ug

MEK 200 MEK 2 mg

Acetone 500 Acetone 50 mg

Methanol 200 Yes Methanol 15 mg

Xylene 100 Methylhippuric

Acid 1.5 g/g Cr.

Isopropanol 200 Yes

Site Visit

Large open bays

Multiple solvents present

Storage locker of old solvent products

Confirmed that other workers report similar symptoms, less severe

Management concerned, willing to stop use of n-hexane containing products

Diagnosis and Course Toxic Peripheral Neuropathy due to n-

hexane solvent exposure, likely potentiated by exposure to multiple other solvents

Course: – Removed from further exposure– Off work for 2 1/2 years– Gradual return of function– Residual numbness of lower extremities 3 years

later

Reference: n-Hexane--Related Peripheral Neuropathy Among Automotive Technicians --California, 1999—2000 http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5045a3.htm