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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