A call from 40 public health scientists for an end to the continuing humanitarian and environmental catastrophe in Gaza.

An under-recognised aspect of the current humanitarian catastrophe in Gaza is the impact of the war on the environment and the associated risks for human health. This commentary contextualises these impacts against the background of human suffering produced by the overwhelming violence associated with the use of military force against the general population of Gaza. In calling for an immediate cessation to the violence, the authors draw attention to the urgent need to rebuild the health care system and restore the physical and human infrastructure that makes a liveable environment possible and promotes human health and well-being, especially for the most vulnerable in the population. Environmental remediation should therefore form one of the most important parts of international efforts to assist reconstruction, through which we hope Palestinians and Israelis will achieve lasting peace, health, and sustainable development, all as part of accepted international human rights obligations.

Social Inequities in the Survival of Liver Cancer: A Nationwide Cohort Study in Korea, 2007-2017.

BACKGROUND: To analyze the effects of socioeconomic status (type of insurance and income level) and cancer stage on the survival of patients with liver cancer in Korea. METHODS: A retrospective cohort study was constructed using data from the Healthcare Big Data Platform project in Korea between January 1, 2007, and December 31, 2017. A total of 143,511 patients in Korea diagnosed with liver cancer (International Classification of Diseases, 10th Revision [ICD-10] codes C22, C220, and C221) were followed for an average of 11 years. Of these, 110,443 died. The patient's insurance type and income level were used as indicators of socioeconomic status. Unadjusted and adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using a Cox proportional hazards regression model to analyze the relationship between the effects of sex, age, and cancer stage at first diagnosis (Surveillance, Epidemiology, and the End Results; SEER), type of insurance, and income level on the survival of patients with liver cancer. The interactive effects of the type of insurance, income level, and cancer stage on liver cancer death were also analyzed. RESULTS: The lowest income group (medical aid) showed a higher risk for mortality (HR (95% CI); 1.37 (1.27-1.47) for all patients, 1.44 (1.32-1.57) for men, and 1.16 (1.01-1.34) for women) compared to the highest income group (1-6) among liver cancer (ICD-10 code C22) patients. The risk of liver cancer death was also higher in the lowest income group with a distant cancer stage (SEER = 7) diagnosis than for any other group. CONCLUSION: Liver cancer patients with lower socioeconomic status and more severe cancer stages were at greater risk of death. Reducing social inequalities is needed to improve mortality rates among patients in lower social class groups who present with advanced cancer.

Widening Social Inequalities in Cancer Mortality of Children Under 5 Years in Korea.

BACKGROUND: To investigate the effect of parental social class on cancer mortality in children under 5 in Korea, two birth cohorts were constructed by linking national birth data to under-5 death data from the Statistics Korea for 1995-1999 (3,323,613 births) and 2010-2014 (2,297,876 births). METHODS: The Cox proportional hazards model adjusted for covariates was used in this study. RESULTS: Social inequalities of under-5 cancer mortality risk in paternal education and paternal employment status were greater in 2010-2014 than in 1995-1999. The gap of hazard ratio (HR) of under-5 cancer mortality between lower (high school or below) and higher (university or higher) paternal education increased from 1.23 (95% confidence interval, 1.041.46) in 1995-1999 to 1.45 (1.11-1.97) in 2010-2014; the gap of HR between parents engaged in manual work and non-manual work increased from 1.32 (1.12-1.56) in 1995-1999 to 1.45 (1.12-1.89) in 2010-2014 for fathers, and from 1.18 (0.7-1.98) to 1.69 (1.03-2.79) for mothers. When the parental social class was lower, the risk of under-5 cancer mortality was higher in not only adverse but normal births. CONCLUSION: Social inequalities must be addressed to reduce the disparity in cancer mortality of children under 5 years old.

Environmental exposure to asbestos and the risk of lung cancer: a systematic review and meta-analysis.

Asbestos is a carcinogen associated with lung cancer, but few studies have examined the increased risk of lung cancer due to environmental asbestos exposure. We performed a systematic review and meta-analysis to evaluate the association between environmental asbestos exposure and lung cancer. We searched for articles on non-occupational or environmental asbestos exposure and lung cancer in PubMed, EMBASE, CINAHL and Web of Science databases. Our review included 15 studies, and except studies on ingestion exposure we performed a meta-analysis for 13 studies with respect to the type of exposure (neighbourhood and domestic/household exposure). Subgroup analyses and meta-regression were also performed. A significant increase in the risk of lung cancer was found for neighbourhood exposure (1.48, 95% CI 1.18 to 1.86), while the risk was not significantly increased for domestic/household exposure (1.04, 95% CI 0.85 to 1.27). With regard to neighbourhood exposure, naturally occurring asbestos and women were both associated with a higher risk of lung cancer; however, such an increase was not significantly greater compared with that associated with other sources of asbestos exposure and men. Although cautious interpretation is needed due to the large degree of heterogeneity and the small number of included studies, our findings imply that living near the source of asbestos increases the risk of lung cancer.

Occupational exposure to formaldehyde and risk of lung cancer: A systematic review and meta-analysis.

BACKGROUND: Formaldehyde exposure is associated with nasopharyngeal cancer and leukemia. Previously-described links between formaldehyde exposure and lung cancer have been weak and inconsistent. We performed a systematic review and meta-analysis to evaluate quantitatively the association between formaldehyde exposure and lung cancer. METHODS: We searched for articles on occupational formaldehyde exposure and lung cancer in PubMed, EMBASE, Web of Science, and CINAHL databases. In total, 32 articles were selected and 31 studies were included in a meta-analysis. Subgroup analyses and quality assessments were also performed. RESULTS: The risk of lung cancer among workers exposed to formaldehyde was not significantly increased, with an overall pooled risk estimate of 1.04 (95% confidence interval [CI], 0.97-1.12). The pooled risk estimate of lung cancer was increased when higher exposure studies were considered (1.19; 95% CI, 0.96-1.46). More statistically robust results were obtained when high quality (1.13; 95% CI, 1.08-1.19) and recent (1.13; 95% CI, 1.07-1.19) studies were used in deriving pooled risk estimates. CONCLUSIONS: No significant increase in the risk of lung cancer was evident in the overall pooled risk estimate; even in higher formaldehyde exposure groups. Our findings do not provide strong evidence in favor of formaldehyde as a risk factor for lung cancer. However, since risk estimates were significantly increased for high-quality and recent studies, the possibility that exposure to formaldehyde can increase the risk of lung cancer might still be considered.

Exposure to asbestos and the risk of colorectal cancer mortality: a systematic review and meta-analysis.

Asbestos exposure is associated with mesothelioma and cancer of the lung, larynx and ovary. However, the association between asbestos exposure and colorectal cancer is controversial despite several systematic reviews of the literature, including a number of meta-analyses. We performed a systematic review and meta-analysis to evaluate quantitatively the association between exposure to asbestos and colorectal cancer. We searched for articles on occupational asbestos exposure and colorectal cancer in PubMed, EMBASE and Web of Science published before April 2018. In total, 44 articles were selected and 46 cohort studies were analysed. The overall pooled risk estimates and corresponding 95% CIs of the association between occupational asbestos exposure and colorectal cancer were calculated using a random-effects model. Subgroup analyses and sensitivity tests were also performed. There was a significantly increased risk of colorectal cancer mortality among workers exposed to asbestos occupationally, with an overall pooled SMR of 1.16 (95% CI: 1.05 to 1.29). The pooled SMR for colorectal cancer was elevated in studies in which the asbestos-associated risk of lung cancer was also elevated (1.43; 95% CI: 1.30 to 1.56). This implies that the risk of colorectal cancer mortality increases as the level of asbestos exposure rises. A sensitivity analysis showed robust results and there was no publication bias. Although the effect size was small and the heterogeneity among studies was large, our findings indicate that occupational exposure to asbestos is a risk factor for colorectal cancer.

Inhalation Lung Injury Associated with Humidifier Disinfectants in Adults.

We recently established a novel disease entity presented as progressive respiratory failure associated with the inhalation of humidifier disinfectants. In April 2011, we encountered a series of peripartum patients with complaints of respiratory distress of unknown etiology, which was an uncommon phenomenon. Accordingly, we created a multidisciplinary team comprising intensivists, radiologists, pathologists, epidemiologists, and the Korea Centers for Disease Control and Prevention (KCDC). Further, we defined the disease entity and performed a case-control study, epidemiologic investigation, and animal study to determine the etiology. The study findings indicated that the lung injury outbreak was related to the inhalation of humidifier disinfectants and showed that household chemical inhalation can cause severe respiratory failure. Following the withdrawal of humidifier disinfectants from the Korean market in 2012, no such cases were reported. This tragic event is a warning that appropriate safety regulations and monitoring for potential toxic household chemicals are critical to protect public health.

Working hours and self-rated health over 7 years: gender differences in a Korean longitudinal study.

BACKGROUND: To investigate the association between long working hours and self-rated health (SRH), examining the roles of potential confounding and mediating factors, such as job characteristics. METHODS: Data were pooled from seven waves (2005-2011) of the Korean Labour and Income Panel Study. A total of 1578 workers who consecutively participated in all seven study years were available for analysis. A generalized estimating equation for repeated measures with binary outcome was used to examine the association between working hours (five categories; 20-35, 36-40, 41-52, 53-68 and ≥ 69 h) and SRH (two categories; poor and good health), considering possible confounders and serial correlation. RESULTS: Associations between working hours and SRH were observed among women, but only for the category of the shortest working hours among men. The associations with the category of shortest working hours among men and women disappeared after adjustment for socioeconomic factors. Among women, though not men, working longer than standard hours (36-40 h) showed a linear association with poor health; OR = 1.41 (95% CI = 1.08-1.84) for 52-68 working hours and OR = 2.11 (95% CI = 1.42-3.12) for ≥ 69 working hours. This association persisted after serial adjustments. However, it was substantially attenuated with the addition of socioeconomic factors (e.g., OR = 1.66 (95% CI = 1.07-2.57)) but only slightly attenuated with further adjustment for behavioural factors (e.g., OR = 1.63 (95% CI = 1.05-2.53)). The associations with job satisfaction were significant for men and women. CONCLUSIONS: The worsening of SRH with increasing working hours only among women suggests that female workers are more vulnerable to long working hours because of family responsibilities in addition to their workload.

1-Hydroxypyrene and oxidative stress marker levels among painting workers and office workers at shipyard.

OBJECTIVES: The objective of this study was to assess the association between exposure to polycyclic aromatic hydrocarbons (PAHs) and oxidative stress among shipyard workers. METHODS: We recruited 82 painting workers in a shipyard and age/sex matched 137 office workers from the same shipyard company. Urine samples were used to assess for 1-hydroxypyrene (1-OHP) as an exposure biomarker for PAHs and to assess for 8-iso-prostaglandin F2α (iPF) as a biomarker for oxidative stress. Demographics, smoking, alcohol consumption, and working conditions information were obtained from a questionnaire survey. RESULTS: Geometric mean concentration (±standard deviation) of urinary 1-OHP among painting workers (587.9 ± 3.45 ng/g creatinine) was approximately 6.9 times higher than that among office workers (85.6 ± 2.09 ng/g creatinine; P value < 0.001). Compared to the office workers (163.5 ± 1.84 ng/g creatinine), the painting workers (190.6 ± 1.64 ng/g creatinine) had significantly higher urinary levels of iPF (P value = 0.044). Smokers had significantly higher urinary levels of iPF than nonsmokers in both painting workers (smokers 217.0 ± 1.63; nonsmokers 159.2 ± 1.52 ng/g creatinine; P value = 0.011) and office workers (smokers 181.3 ± 1.79; nonsmokers 138.4 ± 1.90 ng/g creatinine; P value = 0.015). Smokers among office workers had higher urinary levels of iPF than nonsmokers among painting workers, but difference was not significant. CONCLUSION: Our results demonstrated that among shipyard workers, painting works were significantly associated with the exposure to PAHs, compared with the office works. However, iPF should be cautiously used to characterize the oxidative stress associated with the occupational PAHs exposure, because iPF is substantially affected by other factors such as smoking status.

Fine particle air pollution and mortality: importance of specific sources and chemical species.

BACKGROUND: While exposure to ambient fine particles <2.5 µm in aerodynamic diameter (PM2.5) has well-established health effects, there is limited quantitative evidence that links specific sources of PM2.5 with those effects. This study was designed to examine the risks of exposure to chemical species and source-specific PM2.5 mass on mortality in Seoul, Korea, a highly populated city. METHODS: We compare daily mortality counts with PM2.5 chemical speciation data collected every 3 days, as well as nine sources of PM2.5 mass resolved by a positive matrix factorization receptor model, from March 2003 through November 2007. A Poisson generalized linear model incorporating natural splines was used to evaluate associations of PM2.5 chemical species and sources with mortality. RESULTS: PM2.5 mass and several chemical species were associated with mortality. Organic carbon, elemental carbon, and lead were associated with mortality outcomes when using multipollutant models adjusted for other chemical species levels. Source-apportioned PM2.5 derived from mobile sources (ie, gasoline and diesel emissions) and biomass burning was associated with respiratory mortality and cardiovascular mortality, respectively. There were moderate associations of industry and of roadway emissions with cardiovascular mortality. CONCLUSIONS: Local combustion sources may be particularly important contributors to PM2.5, leading to adverse health effects.

Exposure characteristics of familial cases of lung injury associated with the use of humidifier disinfectants.

BACKGROUND: This study describes 17 families with 38 lung injury patients (14 males, 24 females; 22 preschool-age children less than six years of age and 16 individuals of 13-50 years) who used disinfectant added to humidifiers in the home. METHODS: Clinical examination and humidifier disinfectant-use histories were taken, and a thorough home investigation was performed to assess exposure to humidifier disinfectant. RESULTS: Nine of the patients (three pregnant females, six preschool-age children) died soon after they first developed lung damage. Six (16%) were pregnant females and 22 (58%) were preschool-aged children younger than six years. The patients used humidifier disinfectant products containing either polyhexamethylene guanidine phosphate (PHMG, n = 36) or oligo(2-(2-ethoxy)ethoxyethyl guanidinium chloride (PGH, n = 2). Twenty-six patients (68%) used the brand "Oxy"®, which contains PHMG. Of the ten patients with fatal lung injury, nine were found to have used PHMG. CONCLUSIONS: Our findings suggest that the use of humidifier disinfectant products containing either PGH or PHMG can cause lung injury, especially in preschool-age children younger than six years and pregnant women.

The health impacts of semiconductor production: an epidemiologic review.

BACKGROUND: Despite concerns over the harmful health effects of semiconductor production, epidemiological studies have shown mixed results. OBJECTIVES: We aim to critically appraise epidemiologic studies to date, and to suggest future research and actions to protect workers in semiconductor industry. METHODS: Epidemiologic studies were identified through electronic database searches, review of reference lists of relevant published works, and expert consultations, and were narratively reviewed. RESULTS: Most evidence suggests reproductive risks from fabrication jobs, including spontaneous abortion (SAB), congenital malformation, and reduced fertility. Although chemicals have been suspected as causal agents, knowledge of the likely contribution(s) from specific exposures is still limited. Evidence of cancer risk seems to be equivocal. However, the available studies had serious limitations including healthy worker effects (HWEs), information bias, and insufficient power, all of which are associated with underestimation. Nevertheless, excess risks for non-Hodgkin's lymphoma (NHL), leukemia, brain tumor, and breast cancer were observed. CONCLUSIONS: Monitoring and innovative research based on international collaboration with a focus on sentinel events are required.

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.

Social inequality in birth outcomes in Korea, 1995-2008.

Social inequality in adverse birth outcomes has been demonstrated in several countries. The present study examined the separate and joint effects of parental education and work in order to investigate the causal pathways of social class effects on adverse birth outcomes in Korea. The occurrence of low birth weight, preterm births, and intrauterine growth retardation was examined among 7,766,065 births in Korea from 1995 to 2008. The effect of social inequality, as represented by parental education and work, was examined against adverse birth outcomes using multivariate logistic regression after controlling for other covariates. Parental education had the most significant and greatest effect on all three adverse outcomes, followed by parental work and employment, which had lesser effects. For adverse birth outcomes, the gap between educational levels increased steadily in Korea from 1995 to 2008. Throughout the analysis, the effect of maternal manual work on adverse birth outcomes was apparent in the study results. Given this evidence of social inequality in education and employment, social interventions should aim at more in-depth and distal determinants of health.

Why some, but not all, countries have banned asbestos.

BACKGROUND: Out of 143 countries that consumed asbestos between 2003 and 2007, only 44 have banned asbestos. This study tried to explain why some countries have banned asbestos while others have not, based on a synthesis that asbestos ban policy of a country will rely on a process of cognition of threats and exploration of safer alternatives. METHOD: As we hypothesized that increased social cost of mesothelioma, capacity of health-related infrastructures, and policy diffusion from adjacent countries were related to asbestos ban adoption, published databases of asbestos ban years, mesothelioma mortality, country rankings in health care and human rights standings, and distribution of banning countries over 14 regions were analyzed accordingly. RESULTS: The average mesothelioma death rate was significantly higher for countries with asbestos bans than in those with no ban (4·59 versus 1·83/million). No-ban countries had less well-developed health-related infrastructures. Among European countries, there was a tendency toward geographical diffusion of asbestos ban policy from Nordic to Western and then other European countries over the years. Even though aberrant cases were also noted where bans were instituted even without mesothelioma database, these were rather exceptions than rules. CONCLUSION: Risk cognition is a complex process, but the presence of well-functioning health infrastructures, as well as the increased social cost of mesothelioma, that can make the plight of asbestos victims visible to the eyes of public and policy makers, may have contributed to this process. Asbestos ban policy from adjacent countries might have facilitated the adoption of alternative solutions.

Periodontitis could be related factors on metabolic syndrome among Koreans: a case-control study.

AIM: Several studies have suggested that metabolic disorders are related to periodontitis. The objective of this study is to assess whether periodontitis is associated with the metabolic syndrome (MetS) among Koreans. MATERIAL AND METHODS: This case-control study was performed among 167 cases with MetS and 166 healthy controls from Shiwha-Banwol Environmental Health Cohort (N = 1853). The community periodontal index (CPI) was used to assess periodontitis (CPI 3-4). MetS was an outcome variable and periodontitis was a main explanatory variable. Age-gender-matched conditional logistic regression models were applied. Monthly household income, smoking, drinking, physical activity and diabetes mellitus were factored as confounders. We also performed stratified analyses according to confounders. RESULTS: Those with periodontitis are more likely to be patients with MetS than those without periodontitis. The adjusted odds ratio of periodontitis for MetS was 1.76. There was no significant dose-effect response on the relationship between the number of sextants with periodontitis and MetS. Links became higher in adults aged 45-60 years and adults without diabetes mellitus. CONCLUSIONS: These results suggest that periodontitis could be an independently related factor on MetS. Hence, dentists and physicians should be aware of the importance of periodontitis as a potential source of inflammatory burden.

Gingival crevicular fluid levels of matrix metalloproteinases cross-sectionally related to periodontitis and metabolic syndrome in community Koreans.

BACKGROUND: Metabolic syndrome (MetS) may be associated with periodontitis. This study aimed to investigate whether the existence of periodontitis and MetS is cross-sectionally associated with matrix metalloproteinase (MMP) in gingival crevicular fluid (GCF) among community Koreans. MATERIALS AND METHODS: Medical and periodontal parameters were evaluated by physicians and dentists in 314 subjects (199 healthy, 58 only periodontitis, 34 only MetS and 23 both). The community periodontal index was used to assess periodontitis. MMP-8, 9, 13 were determined by enzyme-linked immunosorbent assay. Age, gender, monthly household income, smoking and drinking were interviewed as confounders. Analysis of covariance (ANCOVA) was applied. Gender-stratified analyses were applied. RESULTS: After controlling for various confounders, MMP-8, MMP-9 and MMP-13 in GCF were significantly associated with periodontitis in both genders and MMP-9, MMP-13 were associated with MetS in women. MMP-8, MMP-9 and MMP-13 showed association with periodontitis-MetS coexistence non-synergistically in both genders. MMP-9 was synergistically associated with periodontitis-MetS coexistence in women. CONCLUSION: Our results suggest that MMP-8, MMP-9, MMP-13 in GCF were independently related to coexistence of periodontitis and MetS. MMP-9 and MMP-13 could be an appropriate common indicator of periodontitis and MetS in women. Further studies might guarantee that MMPs in GCF could screen periodontitis and MetS.

Lung function decline and blood lead among residents nearby to industrial complex.

PURPOSE: This study was to ascertain the risk factors of pulmonary function decline (forced expiratory volume in 1 s [FEV(1)], forced vital capacity [FVC]) among those exposed to lead in the vicinity of industrial complex. METHODS: In total, 263 men and women, aged over 30, were recruited from two cities during a 2-year follow-up. Spirometry testing was conducted first at baseline and then after 2-years of follow-up. The change in FVC and FEV(1) during the study period was analyzed according to blood lead (BPb), urinary cotinine, and 1-hydroxypyrene, after controlling for sex, height, baseline FVC or FEV(1), and airway hyperresponsiveness. RESULTS: With increase in age, both FEV(1) and FVC declined. More marked decline in FVC was noted for men than for women (p < 0.05), while the decline in FEV(1) was not. Biological variables, especially height (p < 0.05) and pulmonary status (p < 0.0001), were associated with the decline in both FEV(1) and FVC. Even after controlling these other variables, blood lead level was also significantly associated with the decline of FVC. CONCLUSIONS: Even though the decline in FEV(1) and FVC with aging was within a normal range, people with smaller height were more vulnerable to the decline of both FEV(1) and FVC and especially higher level of BPb was accompanied with larger decline of FVC. Oxidative stress in relation to lead accumulation in adult may contribute to rapid aging of pulmonary function.

Income-based disparities in the risk of distant-stage cervical cancer and 5-year mortality after the introduction of a National Cancer Screening Program in Korea.

OBJECTIVES: This study assessed the socioeconomic gradient in the risk of distant-stage cervical cancer (CC) at presentation and 5-year mortality for new CC patients after the introduction of a national Cancer Screening Program (NCSP) in Korea. METHODS: All new CC cases from 2007 to 2017 were retrieved from the Korea Central Cancer Registry database linked with the National Health Information Database of the National Health Insurance Service. The age-standardized cumulative incidence of CC, adjusted odds ratios (ORs) of distant metastasis at presentation, and adjusted all-cause mortality hazard ratios (HRs) within 5 years post-diagnosis were assessed according to the income gradient. RESULTS: The 11-year age-standardized cumulative incidence of CC ranged from 48.9 to 381.5 per 100,000 women, with the richest quintile having the highest incidence. Of 31,391 new cases, 8.6% had distant metastasis on presentation, which was most frequent among Medical Aid beneficiaries (9.9%). Distant-stage CC was more likely when the income level was lower (OR, 1.46; 95% confidence interval [CI]), 1.28 to 1.67 for the lowest compared to the richest) and among Medical Aid beneficiaries (OR, 1.50; 95% CI, 1.24 to 1.82). The 5-year mortality was greater in the lower-income quintiles and Medical Aid beneficiaries than in the richest quintile. CONCLUSIONS: The incidence of CC was higher in the richest quintile than in the lower income quintiles, while the risk of distant-stage CC and mortality was higher for women in lower income quintiles in the context of the NCSP. A more focused approach is needed to further alleviate disparities in the timely diagnosis and treatment of CC.