Food safety risk assessment for estimating dietary intake of sulfites in the Taiwanese population.

The purpose of this study was to assess the health risk associated with dietary intake of sulfites for Taiwanese general consumers by conducting a total diet study (TDS). We evaluated the exposure of Taiwanese to sulfites in the diet and its associated health risk. This study used a list of 128 food items representing 83% of the total daily diet. Among the 128 food items, 59 items may contain sulfites. Samples of the 59 food items were collected and subjected to chemical analysis to determine the sulfur dioxide concentration. Health risk was assessed by calculating the ratio of exposure level to the acceptable daily intake (ADI) level of the analyte. For high-intake consumers, the HI of sulfites was 19.7% ADI for males over the age of three years at the 95th percentile; whereas for females over the age of 66, the HI was 17.8% ADI. The HI for high-intake consumers was above 10% ADI. This suggests that regulatory actions must be continued and that consumers should be advised to be aware of processed foods with relatively high contamination to avoid excessive exposure.

High serum iron is associated with increased cancer risk.

Epidemiologic studies linking high serum iron with cancer risks are limited and inconclusive, despite evidence implicating body iron in human carcinogenesis. A cohort of 309,443 adults in Taiwan who had no history of cancer had serum iron levels tested at the time of recruitment (1997-2008). Initially measured iron levels were associated with subsequent cancer risk by linking individuals with the National Cancer Registry and National Death File. HRs were calculated by the Cox model. One third of males (35%) and one fifth of females (18%) had high serum iron (≥120 µg/dL), which was associated with a 25% increase in risk for incidence of all cancers [HR, 1.25; 95% confidence interval (CI), 1.16-1.35] and with a 39% increase in risk for mortality from all cancers (HR, 1.39; 95% CI, 1.23-1.57). The relationship between serum iron and cancer risk was a J-shaped one, with higher cancer risk at both ends, either at lower than 60 µg/dL or higher than 120 µg/dL. At the higher end, cancer risk increased by 4% for every 10 µg/dL increment above 80 µg/dL, showing a dose-response relationship, with 60 to 79 µg/dL as a reference level. In a sensitivity analysis, the increases in risk were still observed after the first 5 years of cancer cases were excluded. Liver cancer risk was increased in HBV (-) non-hepatitis B carrier (3-fold) and HBV (+) hepatitis B carrier (24-fold). Lifestyle risks such as smoking, drinking, or inactivity interacted synergistically with high serum iron and significantly increased the cancer risks. The liver (HR, 2.49; 95% CI, 1.97-3.16) and the breast (HR, 1.31; 95% CI, 1.01-1.70) were the two major cancer sites where significant cancer risks were observed for serum iron either ≥120 µg/dL or ≥140 µg/dL, respectively. This study reveals that high serum iron is both a common disorder and a marker of increased risk for several cancers.

ERα phenotype, estrogen level, and benzo[a]pyrene exposure modulate tumor growth and metabolism of lung adenocarcinoma cells.

Women have a higher risk of lung adenocarcinoma than men, suggesting that estrogen pathway may be involved in the pathogenesis of this cancer. This study was designed to determine whether ERα expression, estrogen levels, and endocrine disruptor exposure would influence tumor growth of lung adenocarcinoma cells using a xenograft model in which human lung adenocarcinoma cells with and without transgenic ERα expression were transplanted into female nude mice. Results showed that estrogen promoted tumor growth of ERα(+) lung adenocarcinoma cells but inhibited that of ERα(-) lung adenocarcinoma cells. Endocrine disruptor benzo[a]pyrene stimulated ERα(-) tumor growth dose dependently. Either of ovariectomy and ERα expression abolished the tumor growth-promoting effect of benzo[a]pyrene. The high CYP1B1/CYP1A1 and low COMT/CYP1B1 expression ratios detected in ERα(+) tumors suggested an accumulation of 4-hydroxyestradiol metabolite under high body estrogen, whereas comparable CYP1A1 and CYP1B1 expression plus estrogen-inducible COMT expression might favor the formation of 2-methoxyestradiol in ERα(-) tumors. Inhibition of estrogen on ERα(-) tumor growth might be partly attributable to the anti-proliferative action of 2-methoxyestradiol. Benzo[a]pyrene increased expression of CYP1B1 over CYP1A1 and suppressed estrogen-induced COMT up-regulation in ERα(-) tumor cells, probably switching estrogen metabolism to 4-hydroxyestradiol formation and removing the inhibition of 2-methoxyestradiol on ERα(-) tumors. ERα inhibited AhR from up-regulating CYP1 in response to benzo[a]pyrene exposure, but it increased angiogenic VEGF-A expression with body estrogen levels. Estrogen might increase ERα(+) lung adenocarcinoma growth by up-regulating cancer-related ERα target gene expression.

A GIS-aided assessment of the health hazards of cadmium in farm soils in central Taiwan.

A geostatistical method was developed to examine the correlation, or lack of it, between the levels of cadmium (Cd) detected in farm soils and those detected in the human specimens collected from residents around the contaminated areas in Changhua County where cadmium contamination of staple rice has been documented. We used the Taiwan EPA environment data in 2002 and human data which were generated by the National Health Research Institutes during 2003-2005. Kriging interpolation methods were used to determine soil Cd concentrations. A Zonal statistical function was performed to assess the individual exposure. Soil Cd levels and tissue Cd levels in residents were analyzed for contamination hotspots and other areas to determine correlation between the two variables. Three Cd contamination hotspots were identified, in which no correlation was found between soil Cd levels and tissue Cd levels in residents. Our results demonstrate how GIS spatial modeling technique can be used to estimate distribution of pollutants in an area using a limited number of data points. Results indicated no association between the soil contamination and the exposure of residents to Cd, suggesting that both the soils and the residents are receptors of Cd as a pollutant from as yet unidentified sources.

Polycyclic aromatic hydrocarbons in cigarette sidestream smoke particulates from a Taiwanese brand and their carcinogenic relevance.

Polycyclic aromatic hydrocarbons (PAHs) adsorbed on cigarette sidestream smoke particulates (CSSPs) have been regarded as important contributors to lung carcinogenesis in never smokers. However, limited information is available on PAH levels in cigarette sidestream smoke. Here we determine the concentrations of 22 PAHs, including 16 US EPA priority PAHs, in CSSPs generated from a high market-share domestic brand in Taiwan. Five of the 22 PAHs are undetectable. The remaining 17 PAHs constitute about 0.022% of the total mass of CSSPs. Near one fifth of the PAH mass come from IARC group 1 and group 2 carcinogens. Carcinogenic potency is equivalent to 144 ng benzo[a]pyrene per cigarette converted according to potency equivalency factors (PEFs). The CSSP condensate could activate AhR activity and induce AhR target gene expression. High concentrations of CSSPs also exhibited AhR-independent cytotoxicity. However, mixing the 17 PAHs as the composition in the CSSP condensate could not reconstitute either capacity. Since AhR activation and cytotoxicity are important mechanisms underlying carcinogenic potency, the results suggest that other component compounds play a more active role in carcinogenesis. The approach of individual PAH profiling plus PEF conversion commonly used in risk assessment is likely to underestimate the risk caused by environmental cigarette smoke exposure.

Inorganic arsenic exposure and its relation to metabolic syndrome in an industrial area of Taiwan.

Past arsenic exposure was found associated with increased incidence of type 2 diabetes. However, the mechanisms remain unclear. Metabolic syndrome has been shown as a strong predictor for diabetes occurrence. We aimed at examining the association of inorganic arsenic exposure and the prevalence of metabolic syndrome. The authors recruited 660 age and gender stratified random population of residents in central Taiwan during 2002-2003. They received home interviews and health examinations at local health care units, where blood and hair specimens were collected. Hair arsenic (H-As) concentrations were determined by inductively coupled plasma-mass spectrometry. Metabolic syndrome was defined as the presence of three or more of the following risk factors: elevated levels of blood pressure, plasma glucose, and triglycerides, also the body mass index, and reduced high-density lipoprotein. Prevalence of metabolic syndrome increased from the 2nd tertile (0.034 ug/g) of H-As levels (odds ratio=2.54, 95% confidence interval: 1.20-5.39, p=0.015) after the adjustment for age, gender, occupation and life styles including cigarette smoking. We further found linear relation between H-As concentrations and increased levels of plasma glucose and lipids, and blood pressures. This first report may help identify modifiable factors associated with diabetogenesis and cardiovascular disease progression and thus be worth following for community health.

Survey of urinary nickel in residents of areas with a high density of electroplating factories.

The soil metal contamination arising from the discharge of the high density of electroplating factories in the geographic center of Taiwan has prompted concern about human exposure to harmful metals. This study aimed to determine the levels of nickel (Ni) in urine of residents living in the high vs. low factory-density areas, and to examine how these levels relate to gender and age. A total of 660 subjects, resident in the area for the last five years, were sampled according to the stratified random sampling approach, at ages 35-44, 45-54, and 55-64years for both genders. Metals in urine samples were analyzed by inductively coupled plasma mass spectrometry (ICPMS). The geometric mean (95% confidence interval (CI)) of urinary Ni was 6.30 (5.99-6.62)mug/l. The 0.95 parametric reference interval (90% CI) of urinary Ni was estimated to be 1.74 (1.62-1.88) to 22.73 (21.14-24.44)mug/l. Subjects in the areas with a high density of electroplating factories had significantly higher urinary Ni levels than those in the low-density areas, but both types of areas had obviously higher urinary Ni levels when compared to the non-occupationally exposed population from western countries. The health significance of elevated urinary Ni and its causative factors remain to be determined.