Polyneuropathy by Occupational Exposure to Acrylamide

Cheong, Hae Kwan; Kwon, Yong Wook; Uh, Kyung Yun; Kim, Byung Joon; Yang, Jeong Sun; Jung, Cheol; Jin, Youngwoo; Lee, Mi Young; Kang, Seong Kyu

Abstract

Authors report a first Korean case of polyneuropathy in an acrylamide producing factory together with an environmental and epidemiologic survey for the ten workers of the same workplace and 46 workers in the production and manufacturing acrylamide in Ulsan, Korea. The case is 30 years old man who worked in the prcduction of the acrylamide for two years. In August, 1997, he had a weakness of the lower extremity with loss of body weight of 15 Kg which progressed to paresthesia of the limbs, the loss of vibration sense, difficulty in walking, speech disturbance, dysuria, constipation, difficulty in erection and swallowing difficulty. Neurologic examination showed a complete loss of vibration and position sense, and loss of deep tendon reflex in all the limbs. There was a contact dermatitis-like skin lesion on the feet. Electrodiagnostic test showed a generalized polyneuropathy of moderate degree involving motor and sensory component of peripheral and cranial nerves. After 8 months' cessation from exposure and supportive care, his symptoms were completely resolved, but abnormality in electrodiagnostic test and vibrotactile perception threshold still persisted, although much improved than before. There were 11 workers in the same workplace of the case, producing acrylamide by microorganism as a catalyst. Environmental monitoring of the workplace revealed air-borne concentration of the acrylamide to be from 0.05 to 0.23 mg/m(3) by personal sampling and from 7.65 to 11.65 mg/m(3) by area sampling during filter exchanging process, which far exceeds TLV-TWA of 0.03 mg/m(3). However acrylamide was not detected from the plasma of the workers. Symptom questionnaire showed a markedly higher complain of neurologic symptoms, compared to the workers of the other acrylamide producing companies. Electrodiagnostic test showed a several workers are in the lower normal range without definite abnormality. Vibrotactile perception threshold by Vibratron II showed a significantly increased threshold in the workers of the same workplace compared to the other acrylamide workers and significantly decreased test score of color vision compared to normal controls. After improvement of the production process and strict wearing of the protective device, most workers reported the improvement of clinical symptoms, but vibrotactile perception threshold was not improved. These result suggests the need for the effective environmental monitoring together with a periodic biological monitoring. Development of effective screening test is urgently needed to control and assess the skin absorption of acrylamide.