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Occupational lung cancer in Bucharest

The cancer for which a direct link with a carcinogenic agent from the workplace can be established is an occupational cancer. The exposure to carcinogenic agents at workplace has low prevalence in the general population. The level of exposure can vary largely according to the job, workplace, and industrial process. It is well recognized that 4% of the total number of incident cancer cases are occupational. Out of 1759306 newly cancer cases diagnosed in Europe each year, 70000 are due to the occupational risk factors.

In Romania a total number of 42907 cancer cases are diagnosed yearly and most probably, 1716 are caused by the occupational exposure to the carcinogenic factors.

If we consider both the sex and the cancer site the estimation of occupational cancers for the main topography would be as follows:
- 80% of the pleural cancers are occupational;
- 15% of the lung cancers in men and 5% of the lung cancers in women’s are occupational;
- 10% of the bladder cancers in men and 5% in women’s are occupational;
- 40% of the sinuses cancers in men and 30% in women’s are occupational;
- 2% of the larynx cancers in men and 1% in women’s are occupational;
- 10% of men leukemia and 5% of women’s leukemia are occupational.

If we apply these data accepted by the experts to the Romanian statistics, the situation would look as follows:
- 5-10 occupational cancers of the pleura;
- 600-900 occupational lung cancers;
- 100-150 occupational bladder cancers;
- 20-30 occupational sinuses cancers;
- 20-30 occupational larynx cancers;
- 80-120 occupational leukemia.

Actually, in Romania only six cancers cases (lung cancer) were recognized as occupational in the latest 4 years. The causes of this serious underestimation are the lack of knowledge among the medical doctors (oncologists, pneumopathologists, general practitioners, and occupational physicians). They do not recognize the suspected cases and consequently do not notify them. Both the medical doctors and the patients are not interested in declaring the occupational cancers because the lack of any benefit. There is also a serious lack of information regarding the occupational cancer risk among the employers and employees. The public health authorities and labor inspection do not have the adequate tools to monitor the risks.

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Taking into account these aspects a working group from the Institute of Public Health in Bucharest, Dep. of Pneumopathology and Oncology investigated between 1998 and 2002 the occupational risk factors and lung cancer in Bucharest. The study was part of a more complex project initiated and coordinated by IARC, Lyon France and financed by The European Commission. The project aimed to evaluate the risk of developing lung cancer after occupational exposure to up to 70 known, possible or probable carcinogenic factors in 6 Central and Eastern European countries and UK. Secondary, in Bucharest the study planned to make an evaluation of the workplaces and jobs at risk.

The study had a case-control design. 180 newly diagnosed cancer cases, hospitalized at “Marius Nasta” Institute, were enrolled after pathological confirmation. A 1:1 matched control group was selected among the patients hospitalized for other non-malignant diseases. The inclusion criteria for cases were age 15 to 75 and permanent residence in Bucharest. The data were collected via direct interview using standardized questionnaires.

An occupational physician and a chemist reviewed each questionnaire to evaluate the intensity and frequency of the exposure for each substance of interest occurred in each job. The intensity indices was calculated on a 1 to 3 scale were each category was weighted according to the local admissible limit value for each substance. The duration of exposure was calculated on a similar scale were each category was weighted for the frequency of exposure asked in the questionnaire. The confidence of exposure (probable, possible, known) was assigned to a same scale of 1 to 3. Each job was coded according to NACE (General Industrial Classification of Economic Activities within European Communities) and ISCO (International Standard Classification of Occupation).

The data were entered into three databases and were annalysed with the STATA package. For the occupational cancer the diagnosis criteria were: well known carcinogenic agents for the lung, included on the list accepted by the Romanian legislation (General Work Protection Regulation), exposure period of more than 10 years, latency period of more than 10 years, indice of confidence „3”.

The preliminary results show low prevalence of the studied exposures (0.05-0.17percentage) comparable with the exposure prevalence in the other Central and Eastern European centers. The preliminary results show low prevalence of the studied exposures (0.05-0.17percentage) comparable with the exposure prevalence in the other Central and Eastern European centers. When calculating the unadjusted OR for a 95% CI the results showed a risk of lung cancer two times higher for the subjects exposed to asbestos. There is also significantly high risk for the subjects exposed to arsenic, cadmium, welding fumes and plastics pyrolisis products.

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There were 226 exposed jobs (job fulfilling the criteria of latency and confidence indices). The welding fumes, chromium, mineral oils and engine emissions were the most frequent exposures (considering only the exposures included on the NGPM list). There was a relatively high occupational stability among subjects with the mean number of job/person equal with 2.7. We diagnosed 75 occupational cancers out of the total of 181 lung cancers. 78% of these had exposures to 1 to 4 different carcinogenic agents during the entire worklife The exposure was more complex for the remaining 22% (5 to 10 different agents). The male/female rate was 8.6 (3.5 for total lung cancer) and the mean age for both sexes was 56.9.

The study describes the pattern of occupational exposure to more than 70 carcinogens in Bucharest and the effect on health (occurrence of occupational cancer). The advantage of the study was the evaluation of the exposure circumstances (type of agent, concentration, exposure frequency, latency, job title, workplace, and protection devices) rather than single exposure. Data from the literature show that attention should be given to individual complex exposure at workplace. The exposure matrices are useful tools only for prospective risk monitoring (assuming an accurate quantitative and qualitative assessment of chemicals). Therefore, the proven presence of the carcinogenic agents at workplace is not enough for the declaration of occupational cancer. In addition, the quantitative measurements are irrelevant for the past exposure level.

The study demonstrated the carcinogenic risk in jobs and workplaces recognized as “non-exposed” (welding, lathe machine operator, plumber, auto repair shop). The men are at higher risk to develop occupational lung cancer than women are. The mean age of 56 confirmed the long latency in occupational lung cancer.

From a public health perspective, the occupational medicine should devote its efforts to two main actions: risk prevention and risk communication. The first step of the prevention is to identify and to describe the risk. Only the exposure data collection, in a standardized way, makes possible to list all the carcinogenic substances in use nationwide. This database would be of great help not only to the health professionals but also to both employers and employees who could find there information regarding the health hazards that relate to each substance. A large ammount of poor quality data collected in an empiric way is of any use.

The quantitative risk characterization by measuring the concentrations of the substances is a secondary objective as long as we can not rely on appropriate tools to determine the complex mixture of carcinogenic agents at workplaces and the limit values are not relevant for the dose-response curve. More important for the current practice would be to create job-exposure matrix which would help to a good description of the past complex exposure. The method allows the practitioner to asign very easy the suspected occupational cases to one or another category.

The only way to proof the occupational cancer risk is to declare the occupational cancers. No one would recognize a risk charcterized by only 6 occupational cancers in an working population of several million people. The information about the risk must be disseminated through all the partners involved: the employers communities, the employees communities, the medical community. However, we should note that the medical doctors are the main responsible for the statistic underestimation of the occupational cancer. Therefore, the oncologists, the pneumologists, the general practitioners and even the occupational health physicians should be trained in an accesible way on how to deal with a suspected case.

The team work (occupational medicine, occupational safety and health, work inspection), is the key action for an accurate risk management in occupational cancer.

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