Review for Retrospective Exposure Assessment Methods Used in Epidemiologic Cancer Risk Studies of Semiconductor Workers: Limitations and Recommendations

This article aims to provide a systematic review of the exposure assessment methods used to assign wafer fabrication (fab) workers in epidemiologic cohort studies of mortality from all causes and various cancers. Epidemiologic and exposure–assessment studies of silicon wafer fab operations in the semiconductor industry were collected through an extensive literature review of articles reported until 2017. The studies found various outcomes possibly linked to fab operations, but a clear association with the chemicals in the process was not found, possibly because of exposure assessment methodology. No study used a tiered assessment approach to identify similar exposure groups that incorporated manufacturing era, facility, fab environment, operation, job and level of exposure to individual hazardous agents. Further epidemiologic studies of fab workers are warranted with more refined exposure assessment methods incorporating both operation and job titleand hazardous agents to examine the associations with cancer risk or mortality.

The relationship between spontaneous abortion and female workers in the semiconductor industry

BACKGROUND: This study investigated the relationship between job type and the risk for spontaneous abortion to assess the reproductive toxicity of female workers in the semiconductor industry. METHODS: A questionnaire survey was administered to current female workers of two semiconductor manufacturing plants in Korea. We included female workers who became pregnant at least 6 months after the start of their employment with the company. The pregnancy outcomes of 2,242 female workers who experienced 4,037 pregnancies were investigated. Personnel records were used to assign the subjects to one of three groups: fabrication process workers, packaging process workers, and clerical workers. To adjust for within-person correlations between pregnancies, a generalized estimating equation was used. The logistic regression analysis was limited to the first pregnancy after joining the company to satisfy the assumption of independence among pregnancies. Moreover, we stratified the analysis by time period (pregnancy in the years prior to 2008 vs. after 2009) to reflect differences in occupational exposure based on semiconductor production periods. RESULTS: The risk for spontaneous abortion in female semiconductor workers was not significantly higher for fabrication and packaging process workers than for clerical workers. However, when we stratified by time period, the odds ratio for spontaneous abortion was significantly higher for packaging process workers who became pregnant prior to 2008 when compared with clerical workers (odds ratio: 2.21; 95% confidence interval: 1.01–4.81). CONCLUSIONS: When examining the pregnancies of female semiconductor workers that occurred prior to 2008, packaging process workers showed a significantly higher risk for spontaneous abortions than did clerical workers. The two semiconductor production periods in our study (prior to 2008 vs. after 2009) had different automated processes, chemical exposure levels, and working environments. Thus, the conditions prior to 2008 may have increased the risk for spontaneous abortions in packaging process workers in the semiconductor industry. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s40557-017-0204-x) contains supplementary material, which is available to authorized users.

The Survey of Occupational Dermatoses in a Semiconductor Industry(II) (1996.6 - 2000.5) / 대한피부과학회지

BACKGROUND: Occupational dermatoses are the most prevalent of all occupational diseases. Over the past few decades, the incidence of occupational dermatoses in Korea is increasing with rapid growth in industry. However, there have been only a few reports about occupational dermatoses in Korean dermatologic literature. OBJECTIVE: The purpose of this article is to study the prevalence of occupational dermatoses in a semiconductor industry and to compare these with previous reports. METHODS: A dermatologist attended regularly at the clinic in a semiconductor industry once a week from June 1995 to May 2000. 4, 985 workers diagnosed with skin disease were analyzed. RESULTS: The results can be summarized as follows: Annual incidences are 6.5%(1995.6-1996.5), 5.3%(1996.6-1997.5), 5.2%(1997.6-1998.5), 5.7%(1998.6-1999.5), 5.8%(1999.6-2000.5) and average incidence is 5.7%. In the distribution of dermatoses as disease groups, eczema(28.8%), fungal infection(19.2%), disease of skin appendage(17.6%), erythema, urticaria and drug eruption(9.4%), viral infection(4.9%), constituted 79.9% of the total. Ten most common dermatoses include contact dermatitis(13.1%), acne(12.5%), tinea pedis(11.2%), urticaria(7.5%), hand eczema(6.6%), seborrheic dermatitis(6.2%), onychomycosis(3.0%), alopecia(2.9%), tinea cruris(1.7%) and lichen simplex chronicus(1.6%). Diseases which shows high seasonal distribution in summer are contact dermatitis, tinea pedis, urticaria, tinea cruris. Contact dermatitis(1.7%), acne(1.6%), chemical burn(1.3%) and hand eczema(1.1%) were the most important occupational dermatoses in this survey. The occupational contact dermatitis and acne mainly came from the mask, hood and dust preventing clothes which the workers must wear for 8 hours a day at their work place. Hydrofluoric acid(1.0%) was the main cause of chemical burn. Hand eczema was primarily due to kitchen work, cleaning work and gloves. The other dermatoses related to occupation were trauma, seborrheic dermatitis, atopic dermatitis, xerosis cutis, urticaria, etc. CONCLUSIONS: Comparing these results about occupational dermatoses with previous report (1992.6-1995.5) in a semiconductor industry before, there was relatively low incidence of hydrofluoric acid burn and high incidence of contact dermatitis, acne and hand eczema.

The Survey of Occupational Dermatoses in a Semiconductor Industry for 3 years / 대한피부과학회지

BACKGROUND: Occupational dermatoses are increasing tendency in Korea. But there were only a few reports about occupational dermatoses in Korean dermatologic literatures. OBJECT: For the effective preventive method and having interest in occupational dermatoses, we have done wide ranged basic study about the occupational dermatoses for 3 years in a semiconductor industry. METHODS: The number of workers of the semiconductor industry was 10,500(male 5,000, female 5,500) and finally the number of analysed patients in this survey was 2,736. A dermatologist attended regularly at the clinic in a semiconductor industry once a week for the duration of 3 years from June 1992 to May 1995. Diagnosis was made by clinical findings and investigation about the working environment. RESULTS: 1. The most common dermatoses are contact dermatitis(14.3%), acne(14.0%), seborrheic dermatitis(7.1%) and tinea pedis(6.9%). Urticaria, hand eczerna, abscess, onychomycosis, t.inea versicol or and chemical burn were also observed frequently. 2. Chemical burn(2.0%), contact dermatitis(1.4%) and acne(0.8%) were the most important occupation related dermatoses in this survey. Hydrofluoric acid(1.4%) was the main cause of chemical burn. The occupationa contact dermatitis and acne in this survey were mainly came from the mask, hood and dust preventing clothes which the workers must wear for 8 hours a day at working place. 3. The other dermatoses related to occupation were hand eczema, trauma, nummular eczema, atopic dermatitis, etc.. CONCLUSION: This study regardless of insufficient inspection equipment was done for a relatively long period in the semiconductor industry. In the future, many studies like this will be reported and the studies will give a model of management of occupational dermatoses in Korea.