• Safety and Health at Work
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• v.9 no.3
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• pp.249-256
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• 2018

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 title and hazardous agents to examine the associations with cancer risk or mortality.

• Safety and Health at Work
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• v.12 no.3
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• pp.396-402
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• 2021

Background: Styrene is one of the aromatic compounds used in acetonitrile-butadiene-styrene (ABS) producing petrochemicals, which has an impact on health of workers. Therefore, this study aimed to investigate the health risks of styrene emitted from the petrochemical industry in Iran. Methods: Air samples were collected based on NIOSH 1501 method. The samples were analyzed by the Varian-cp3800 gas chromatograph. Finally, risk levels of styrene's health effects on employees were assessed by the quantitative method of the U.S. Environmental Protection Agency (U.S. EPA) and the semiquantitative way by the Singapore Occupational Safety and Health Association. Results: Based on the results, the employees had the highest average exposure to styrene vapors (4.06 × 10^-1mg.(kg - day)^-1) in the polybutadiene latex (PBL) unit. Therefore, the most top predictors of cancer and non-cancer risk were 2.3×10^-4 and 7.26 × 10^-1, respectively. Given that the lowest average exposure (1.5 × 10^-2mg.(kg - day)^-1) was in the dryer unit, the prediction showed a moderate risk of cancer (0.8 × 10^-6) and non-cancer (2.3 × 10^-3) for the employees. The EPA method also predicted that there would be a definite cancer risk in 16% and a probable risk in 76% of exposures. However, according to the semiquantitative approach, the rate of risk was at the "low" level for all staff. The results showed that there was a significant difference (p < 0.05) between the units in exposure and health risk of styrene (p < 0.05). Conclusion: Given the high risk of styrene's health effects, appropriate control measures are required to reduce the exposure level.

• Environmental Engineering Research
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• v.24 no.1
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• pp.150-158
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• 2019

Soil contaminated with heavy metals from artisanal gold mining in Anka Local Government Area in Northwestern Nigeria was investigated to evaluate the human health risk as a result of heavy metals. Measured concentration of heavy metals and exposure parameters were used to estimate human carcinogenic and non-carcinogenic risk. GIS-based Kriging method was utilized to create a prediction maps of human health risks and probability maps of heavy metals concentrations exceeding their threshold limits. Hazard index calculation showed that 21 out of 23 locations are posing non-cancer risk for children. Adults and children are at high cancer risk in all locations as the total cancer risk exceeded $1{\times}10^{-6}$ (the lower limit CTR value). Kriging model showed that only a very small area in Anka has a hazard index of less than unity and cumulative target risk of less than $1{\times}10^{-4}$, indicating a significant carcinogenic and non-carcinogenic risks for children. The probability of heavy metals to exceed their threshold concentrations around the study area was also found to be high.

• Journal of Environmental Health Sciences
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• v.47 no.4
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• pp.356-365
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• 2021

Background: Concerns have been raised regarding the criteria of groundwater, in particular in Gwangwon-do Province where many residents drink groundwater due to the poor supply of tap water and a high nonconformity rate with water quality criteria nationwide. Objectives: Water quality monitoring and risk assessment were conducted for groundwater in Hoengseong, Gangwon-do Province. Methods: A total of 46 items required for meeting drinking water criteria were analyzed from 258 samples collected from March 2017 through August 2018 (152 sites in 2017 and 106 sites in 2018). Risk assessment was conducted for two non-carcinogens (F^- and NO₃-N), and one carcinogen (i.e., arsenic) based on their high nonconformity to water quality criteria. Results: Water quality analysis revealed that the total proportion of nonconformities was determined to be 27.9%. The nonconformity rate for each content item is as follows: total colony counts (1.6%), total coliform (6.2%), Escherichia coli (1.2%), F^- (8.1%), arsenic (4.7%), NO₃-N (8.1%), pH (1.2%), manganese (0.4%), and turbidity (5.8%). Risk assessment indicated that fluoride induced a hazard quotient greater than 1 with the 95% UCL (Upper Confidence Limit) concentration of the total 258 sites and average, median, and 95% UCL concentrations of nonconformity sites. For NO₃-N, there was no human health risk. For arsenic, the excess cancer risk exceeded the acceptable cancer risk of 1×10^-6 with the average and 95% UCL concentrations of total 258 sites and average, median, and 95% UCL concentrations of nonconformity sites. Conclusions: This study suggests that it is necessary to expand water quality monitoring of groundwater and conduct a more detailed risk assessment in order to establish a health care plan for the residents of Hoengseong, Gangwon-do Province.

• Toxicological Research
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• v.6 no.1
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• pp.63-73
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• 1990

Human exposure to environmental carcinogens can be detected by a number of methods including immunoassay, $^{32}P-postlabeling$ assay, and fluorescence technique. These assays have been applied to measure biological markers of carcinogen-adducts formed with macromolecules such as DNA, RNA and protein. In an attempt to investigate causal relationships between carcinogen exposure and tumor formation, specific carcinogen-adducts have been quantitated from human tissues and body fluids of cancer patients, occupational workers heavily exposed to certain carcinogens, smokers and controls. Carcinogens studied for biological human monitoring include benzo(a)pyrene, aflatoxin B1, UV light, ethylene oxide, 8-methoxypsoralen, 4-aminobiphenyl, vinyl choride, N-nitrosamine, cisplatin and other chemotherapeutic agents. Relevance of human monitoring for cancer research, progress in this field, methods to detect carcinogen-adducts are reviewed here. It is hoped that these approaches will be used for the risk assessment of carcinogen exposure, cancer etiology study and cancer prevention in humans.

• Toxicological Research
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• v.6 no.1
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• pp.61-61
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• 1990

Human exposure to environmental carcinogens can be detected by a number of methods including immunoassay, $^{32}P$-postlabeling assay, and fluorescence technique. These assays have been applied to measure biological markers of carcinogen-adducts formed with macromolecules such as DNA, RNA and protein. In an attempt to investigate causal relation ships between carcinogen exposure and tumor formation, specific carcinogen-adducts have been quantitated from human tissues and body fluids of cancer patients, occupational workers heavily exposed to certain carcinogens, smokers and controls. Carcinogens studied for biological human monitoring include benzo(a)pyrene, aflatoxin B1, UV light, ethylene oxide, 8-methoxypsoralen, 4-aminobiphenyl, vinyl chloride, N-nitrosamine, cisplatin and other chemotherapeutic agents. Relevance of human monitoring for cancer research, progress in this field, methods to detect carcinogen-adducts are reviewed here. It is hoped that these approaches will be used for the risk assessment of carcinogen exposure, cancer etiology study and cancer prevention in humans.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.213-218
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• 2016

Cancer is a major health problem in the Arab region including Iraq. An adequate database is essential for effective cancer control strategies. Such a database may be provided through cancer registration but supportive household surveys may be useful. This article reports selected results on the feasibility of household surveys to support and validate cancer registration in Basrah governorate - southern Iraq. A large scale multi-stage cluster sample household survey was carried out in Basrah during 2013. It covered 6,999 households and involved gathering data on demographic characteristics and both incident cancer cases and cancer-related deaths among members of these households during a three-year recall period (2010-2012). The data obtained yielded an average annual incidence rate of 91 per 100,000 population (age-standardized incidence rate of 148.8 /100,000) and cancer specific mortality rate of 68 per 100,000 population (age-standardized mortality rate of 126.3/100,000). The results showed an overall pattern of cancer similar to that reported according to cancer registration but the household survey results were consistently higher than those of the cancer registration by a margin of approximately 20- 30% with respect to incident cancer and about 70 % with respect to cancer-specific mortality. Household surveys on cancer, while costly and time consuming, are a very useful additional source of information on cancer at the population level. They can be performed for specific purposes with effective resource mobilization.

• Safety and Health at Work
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• v.12 no.2
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• pp.174-183
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• 2021

Background: Toluene diisocyanate (TDI) is a highly reactive chemical that causes sensitization and has also been associated with increased lung cancer. A risk assessment was conducted based on occupational epidemiologic estimates for several health outcomes. Methods: Exposure and outcome details were extracted from published studies and a NIOSH Health Hazard Evaluation for new onset asthma, pulmonary function measurements, symptom prevalence, and mortality from lung cancer and respiratory disease. Summary exposure-response estimates were calculated taking into account relative precision and possible survivor selection effects. Attributable incidence of sensitization was estimated as were annual proportional losses of pulmonary function. Excess lifetime risks and benchmark doses were calculated. Results: Respiratory outcomes exhibited strong survivor bias. Asthma/sensitization exposure response decreased with increasing facility-average TDI air concentration as did TDI-associated pulmonary impairment. In a mortality cohort where mean employment duration was less than 1 year, survivor bias pre-empted estimation of lung cancer and respiratory disease exposure response. Conclusion: Controlling for survivor bias and assuming a linear dose-response with facility-average TDI concentrations, excess lifetime risks exceeding one per thousand occurred at about 2 ppt TDI for sensitization and respiratory impairment. Under alternate assumptions regarding stationary and cumulative effects, one per thousand excess risks were estimated at TDI concentrations of 10 - 30 ppt. The unexplained reported excess mortality from lung cancer and other lung diseases, if attributable to TDI or associated emissions, could represent a lifetime risk comparable to that of sensitization.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3233-3239
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• 2015

Background: Whether depression causes increased risk of the development of breast cancer has long been debated. We conducted an updated meta-analysis of cohort studies to assess the association between depression and risk of breast cancer. Materials and Methods: Relevant literature was searched from Medline, Embase, Web of Science (up to April 2014) as well as manual searches of reference lists of selected publications. Cohort studies on the association between depression and breast cancer were included. Data abstraction and quality assessment were conducted independently by two authors. Random-effect model was used to compute the pooled risk estimate. Visual inspection of a funnel plot, Begg rank correlation test and Egger linear regression test were used to evaluate the publication bias. Results: We identified eleven cohort studies (182,241 participants, 2,353 cases) with a follow-up duration ranging from 5 to 38 years. The pooled adjusted RR was 1.13(95% CI: 0.94 to 1.36; $I^2=67.2%$, p=0.001). The association between the risk of breast cancer and depression was consistent across subgroups. Visual inspection of funnel plot and Begg's and Egger's tests indicated no evidence of publication bias. Regarding limitations, a one-time assessment of depression with no measure of duration weakens the test of hypothesis. In addition, 8 different scales were used for the measurement of depression, potentially adding to the multiple conceptual problems concerned with the definition of depression. Conclusions: Available epidemiological evidence is insufficient to support a positive association between depression and breast cancer.

• Journal of Environmental Impact Assessment
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• v.28 no.2
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• pp.152-168
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• 2019

The element arsenic, which is abundant in the Earth's crust, is used for various industrial purposes including materials for disease treatment and household goods. Various human activities, such as the disposal of soil waste, metal mining and smelting, and combustion of fossil fuels, have caused the pollution of the environment with arsenic. Recently, guidelines for arsenic in rice have been adopted by the Korean ministry of food and drug safety to prevent health risks based on rice consumption. Because of the exposure to arsenic and its accumulation in the human body through various channels, such as air inhalation, skin contact, ingestion of drinking water, and food consumption, integrated multimedia risk assessment is required to adopt appropriate risk management policies. Therefore, integrated human health risk assessment was carried out in this study using integrated exposure assessment based on multimedia (e.g., air, water, and soil) and multi-route (e.g., oral, inhalation, and dermal) scenarios. The results show that oral uptake via drinking water is the most common pathway of arsenic into the human body, accounting for 57%-96% of the total arsenic exposure. Among various age groups, the highest exposures to arsenic were observed in infants because the body weight of infants is low and the surface areas of infant bodies are large. Based on the results of the exposure assessment, the cancer and non-cancer risks were calculated. The cancer risk for CTE and RME is in the range of 2.3E-05 to 6.7E-05 and thus is negligible because it does not exceed the cancer probability of 1.0E-04 for all age groups. On the other hand, the cancer risk for RME varies from 6.4E-05 to 1.8E-04 and from 1.3E-04 to 1.8E-04 for infants and preschool children, exceeding the excess cancer risk of 1.0E-04. The non-cancer risks range from 5.4E-02 to 1.9E-01 and from 1.5E-01 to 6.8E-01, respectively. They do not exceed the hazard index 1 for all scenarios and all ages.