Transfer of occupational health problems from a developed to a developing country: lessons from the Japan-South Korea experience

The history of occupational health in South Korea

South Korea has experienced rapid economic development over a 60-year period, since the 1960s, rising up from the ruins of the 1950-1953 Korean War. During this short period, South Korea experienced a wide range of occupational safety and health (OSH) problems, similar to that experienced in most developed countries about 100-200 years previously. In response, the South Korean government established a national OSH services system that is on par with most developed countries. In recent years, South Korea now faces a new collection of OSH challenges, such as mental health issues, microenterprise issues, precarious workers, and the promotion of work ability in a rapidly changing socioeconomic structure. This study evaluates the establishment of South Korea's OSH services system, including the socio-politico-economic contexts that have had a profound influence on the system during each historical period.

Work-relatedness of lung cancer by smoking and histologic type in Korea

OBJECTIVES

This study investigated the distribution of causative agents related to occupational lung cancer, their relationships with work, and associations between work-relatedness and the histologic type of lung cancer.

METHODS

We used data from the occupational surveillance system in Korea in 2013. In addition, data from 1,404 participants diagnosed with lung cancer were collected through interviews. We included the patients' longest-held job in the analysis. Work-relatedness was categorized as "definite," "probable," "possible," "suspicious," "none," or "undetermined."

RESULTS

Among the subjects, 69.3% were men and 30.7% were women. Regarding smoking status, current smokers were the most prevalent (35.5%), followed by non-smokers (32.3%), ex-smokers (32.2%). Regarding the causative agents of lung cancer, asbestos (1.0%) and crystalline silica (0.9%) were the most common in definite work-related cases, while non-arsenical insecticide (2.8%) was the most common in probable cases followed by diesel engine exhaust (1.9%) and asbestos (1.0%). Regarding histologic type, adenocarcinoma was the most common (41.7%), followed by squamous cell carcinoma (21.2%). Among current smokers, squamous cell carcinoma was the most common among definite and probable cases (13.4%), while non-small cell lung cancer was the least common (7.1%). Among non-smokers, squamous cell carcinoma was the most common (21.4%), while the least common was adenocarcinoma (1.6%).

CONCLUSIONS

Approximately, 9.5% of all lung cancer cases in Korea are occupational-related lung cancer. Well-known substances associated with lung cancer, such as crystalline silica, asbestos, and diesel engine exhaust, are of particular concern. However, the histologic types of lung cancer related to smoking were inconsistent with previous studies when work-relatedness was taken into account. Future studies are required to clarify the incidence of occupational lung cancer in agricultural workers exposed to non-arsenical insecticides and the associations between work-relatedness and the histologic type of lung cancer.

Global cancer patterns: causes and prevention

Cancer is a global and growing, but not uniform, problem. An increasing proportion of the burden is falling on low-income and middle-income countries because of not only demographic change but also a transition in risk factors, whereby the consequences of the globalisation of economies and behaviours are adding to an existing burden of cancers of infectious origin. We argue that primary prevention is a particularly effective way to fight cancer, with between a third and a half of cancers being preventable on the basis of present knowledge of risk factors. Primary prevention has several advantages: the effectiveness could have benefits for people other than those directly targeted, avoidance of exposure to carcinogenic agents is likely to prevent other non-communicable diseases, and the cause could be removed or reduced in the long term--eg, through regulatory measures against occupational or environmental exposures (ie, the preventive effort does not need to be renewed with every generation, which is especially important when resources are in short supply). Primary prevention must therefore be prioritised as an integral part of global cancer control.

Environmental and occupational interventions for primary prevention of cancer: a cross-sectorial policy framework

BACKGROUND

Nearly 13 million new cancer cases and 7.6 million cancer deaths occur worldwide each year; 63% of cancer deaths occur in low- and middle-income countries. A substantial proportion of all cancers are attributable to carcinogenic exposures in the environment and the workplace.

OBJECTIVE

We aimed to develop an evidence-based global vision and strategy for the primary prevention of environmental and occupational cancer.

METHODS

We identified relevant studies through PubMed by using combinations of the search terms "environmental," "occupational," "exposure," "cancer," "primary prevention," and "interventions." To supplement the literature review, we convened an international conference titled "Environmental and Occupational Determinants of Cancer: Interventions for Primary Prevention" under the auspices of the World Health Organization, in Asturias, Spain, on 17-18 March 2011.

DISCUSSION

Many cancers of environmental and occupational origin could be prevented. Prevention is most effectively achieved through primary prevention policies that reduce or eliminate involuntary exposures to proven and probable carcinogens. Such strategies can be implemented in a straightforward and cost-effective way based on current knowledge, and they have the added benefit of synergistically reducing risks for other noncommunicable diseases by reducing exposures to shared risk factors.

CONCLUSIONS

Opportunities exist to revitalize comprehensive global cancer control policies by incorporating primary interventions against environmental and occupational carcinogens.

Trades of dangers: a study of asbestos industry transfer cases in Asia

BACKGROUND

In a study of asbestos industry transfers in Asia, we examined the transfer of health and safety measures at the time of industry transfer and resulting health outcomes thereafter.

METHODS

Field surveys were conducted in Japan, Germany, Indonesia, and South Korea over a 5 year period beginning in 2007. The surveys involved interviews and field assessments of health and safety conditions.

RESULTS

Even when there were transfers of entire engineering plant processes, we observed that the health and safety measures that should have accompanied the transfer, including technical capacities of risk assessment and management, regulatory protection, and cultural practices, were not actually transferred. According to work environment assessment records, there were differences in airborne asbestos levels of approximately 5-6 fibers/cc between the exporting and importing sides of the transfer. This amounted to a 10 years of time delay in comparable health and safety conditions. These differences resulted in repeated adverse health consequences at each factory operation site.

CONCLUSIONS

Dangerous transfers of asbestos industry technology have occurred repeatedly over the years with the result that Asia has become the largest consumer of asbestos in the world. No effective internationally accepted safety measures have been introduced in the region. The study results support the need for both improved public awareness and international cooperation, such as sharing of substitute material technologies by the exporting countries, and provide the rationale for the creation of an Asian fund for asbestos victims.

Toxic encephalopathy

This article schematically reviews the clinical features, diagnostic approaches to, and toxicological implications of toxic encephalopathy. The review will focus on the most significant occupational causes of toxic encephalopathy. Chronic toxic encephalopathy, cerebellar syndrome, parkinsonism, and vascular encephalopathy are commonly encountered clinical syndromes of toxic encephalopathy. Few neurotoxins cause patients to present with pathognomonic neurological syndromes. The symptoms and signs of toxic encephalopathy may be mimicked by many psychiatric, metabolic, inflammatory, neoplastic, and degenerative diseases of the nervous system. Thus, the importance of good history-taking that considers exposure and a comprehensive neurological examination cannot be overemphasized in the diagnosis of toxic encephalopathy. Neuropsychological testing and neuroimaging typically play ancillary roles. The recognition of toxic encephalopathy is important because the correct diagnosis of occupational disease can prevent others (e.g., workers at the same worksite) from further harm by reducing their exposure to the toxin, and also often provides some indication of prognosis. Physicians must therefore be aware of the typical signs and symptoms of toxic encephalopathy, and close collaborations between neurologists and occupational physicians are needed to determine whether neurological disorders are related to occupational neurotoxin exposure.

A current global view of environmental and occupational cancers

This review is focused on current information of avoidable environmental pollution and occupational exposure as causes of cancer. Approximately 2% to 8% of all cancers are thought to be due to occupation. In addition, occupational and environmental cancers have their own characteristics, e.g., specific chemicals and cancers, multiple factors, multiple causation and interaction, or latency period. Concerning carcinogens, asbestos/silica/wood dust, soot/polycyclic aromatic hydrocarbons [benzo(a) pyrene], heavy metals (arsenic, chromium, nickel), aromatic amines (4-aminobiphenyl, benzidine), organic solvents (benzene or vinyl chloride), radiation/radon, or indoor pollutants (formaldehyde, tobacco smoking) are mentioned with their specific cancers, e.g., lung, skin, and bladder cancers, mesothelioma or leukemia, and exposure routes, rubber or pigment manufacturing, textile, painting, insulation, mining, and so on. In addition, nanoparticles, electromagnetic waves, and climate changes are suspected as future carcinogenic sources. Moreover, the aspects of environmental and occupational cancers are quite different between developing and developed countries. The recent follow-up of occupational cancers in Nordic countries shows a good example for developed countries. On the other hand, newly industrializing countries face an increased burden of occupational and environmental cancers. Developing countries are particularly suffering from preventable cancers in mining, agriculture, or industries without proper implication of safety regulations. Therefore, industrialized countries are expected to educate and provide support for developing countries. In addition, citizens can encounter new environmental and occupational carcinogen nominators such as nanomaterials, electromagnetic wave, and climate exchanges. As their carcinogenicity or involvement in carcinogenesis is not clearly unknown, proper consideration for them should be taken into account. For these purposes, new technologies with a balance of environment and gene are required. Currently, various approaches with advanced technologies--genomics, exposomics, etc.--have accelerated development of new biomarkers for biological monitoring of occupational and environmental carcinogens. These advanced approaches are promising to improve quality of life and to prevent occupational and environmental cancers.

Occupational reproductive function abnormalities and bladder cancer in Korea

The purpose of this study was to review occupational reproductive abnormalities and occupational bladder cancer in Korea and to discuss their toxicological implications. Reproductive dysfunction as a result of 2-bromopropane poisoning was first reported in Korean workers. In 1995, 23 of the 33 workers (25 female and 8 male workers) who were exposed to 2-bromopropane during the assembly of tactile switch parts developed reproductive and/or hematopoietic disorders. A total of 17 (68%) workers were diagnosed with ovarian failure. Two of the eight male workers experienced azoospermia and four workers experienced some degree of oligospermia or reduced sperm motility. In summary, 2-bromopropane poisoning caused severe reproductive effects in Korean workers. The prognosis was poor for reproductive dysfunction. A few cases of occupational bladder cancer have been reported in Korea, whereas other cancers of the urinary tract have not been reported after occupational exposure. A few cases of benzidine-induced cancer have been reported in Korea and 592 workers in Japan have received compensation for benzidine and β-naphthylamine-induced cancer. In conclusion, a few cases of benzidine-induced occupational bladder cancer have been reported in Korea. However, benzidine-induced bladder cancer will likely be an important occupational health issue in Korea in the coming years.

Occupational neurologic disorders in Korea

This article presents a schematic review of the clinical manifestations of occupational neurologic disorders in Korea and discusses the toxicologic implications of these conditions. Vascular encephalopathy, parkinsonism, chronic toxic encephalopathy, cerebellar dysfunction, peripheral neuropathy, and neurodegenerative diseases are common presentations of occupational neurotoxic syndromes in Korea. Few neurotoxins cause patients to present with pathognomic neurologic syndrome. Detailed neurologic examinations and categorization of the clinical manifestations of neurologic disorders will improve the clinical management of occupational neurologic diseases. Physicians must be aware of the typical signs and symptoms of possible exposure to neurotoxins, and they should also pay attention to less-typical, rather-vague symptoms and signs in workers because the toxicologic characteristics of occupational neurologic diseases in Korea have changed from typical patterns to less-typical or equivocal patterns. This shift is likely to be due to several years of low-dose exposure, perhaps combined with the effects of aging, and new types of possibly toxicant-related neurodegenerative diseases. Close collaboration between neurologists and occupational physicians is needed to determine whether neurologic disorders are work-related.