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Abstracts (PDF file, 1.8MB) - Society for Risk Analysis

Abstracts (PDF file, 1.8MB) - Society for Risk Analysis

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SRA 2013 Annual Meeting <strong>Abstracts</strong><br />

M2-E.4 Wu, F*; Liu, Y; Michigan State University;<br />

fwu@msu.edu<br />

Aflatoxin and cyanide: Global burden of disease<br />

Aflatoxin is a toxin produced by certain Aspergillus fungi that<br />

infect food crops, particularly corn, peanuts, and tree nuts<br />

(pistachios, hazelnuts, almonds, walnuts, etc.). It is the most<br />

potent naturally occurring human liver carcinogen known, and<br />

is particularly a danger in the parts of the world where corn<br />

and peanuts are dietary staples. We present our estimates of<br />

the global burden of human liver cancer caused by aflatoxin,<br />

and discuss the potential role of aflatoxin exposure in causing<br />

childhood stunting. Finally, we give a brief discussion of<br />

cyanide in cassava, its adverse effects, and the populations<br />

most at risk worldwide.<br />

P.73 Wu, CH*; Huang, YF; Wu, KY; National Taiwan University;<br />

charlenehwu@gmail.com<br />

Assessing the Health <strong>Risk</strong>s of Dimethyl<strong>for</strong>mamide in an<br />

Occupational Setting<br />

Dimethyl<strong>for</strong>mamide (DMF) is an organic compound able to<br />

induce adverse health effects in humans. It is used in the<br />

production of pharmaceutical products, adhesives, and<br />

synthetic leathers. Employees working in these industries are<br />

likely to be at risk, particularly through inhalation and dermal<br />

absorption. Exposure assessment of DMF was conducted on<br />

106 employees from three synthetic leather plants in Taiwan.<br />

The employees’ urinary samples were collected and<br />

subsequently analyzed. N-methyl<strong>for</strong>mamide (NMF), a DMF<br />

metabolite, is the biomarker identified to measure the body<br />

burden of DMF exposure. Results demonstrated that NMF<br />

concentrations from the majority of urinary samples collected<br />

prior to a work shift were mostly undetectable. However,<br />

urinary concentrations of NMF were significantly higher<br />

post-shift compared to pre-shift. Of the 318 urinary samples<br />

collected, the NMF concentrations in 59 samples exceeded the<br />

American Conference of Industrial Hygienists’ (ACHIH)<br />

recommended Biological Exposure Index (BEI) of 15mg/L. To<br />

assess the health risks of DMF, the reference concentrations<br />

(RfC) were calculated using the Benchmark Dose software. The<br />

benchmark dose, based on existing animal data, is calculated at<br />

3.98 ppm (11.94 mg/m3). Based on this BMDL10, the RfC <strong>for</strong><br />

DMF in these synthetic leather plants is derived at 0.04 ppm<br />

(0.12 mg/m3). The hazard indices <strong>for</strong> all 106 employees (HI)<br />

were also calculated and found that 89.6% of the employees<br />

have a HI value greater than one. Our results demonstrate that<br />

the majority of employees exposed to DMF are subject to<br />

noncarcinogenic adverse health effects, even though the<br />

amount of DMF exposure does not exceed current permissible<br />

exposure limits (PELs) of 10ppm. Further investigation focusing<br />

on the exposure to multiple compounds in these occupational<br />

settings is warranted. A review of risk management protocol of<br />

DMF should be considered since compliance with current<br />

regulations is inadequate in safeguarding health.<br />

P.70 Wu, KY*; Chung, YC; Chen, CC; Hsiao, CH; National<br />

Taiwan University; kuenyuhwu@ntu.edu.tw<br />

Probabilistic <strong>Risk</strong> Assessment with the Bayesian<br />

Statistics Markov Chain Monte Carlo Simulation<br />

US EPA already adopted probabilistic risk assessment (PRA) <strong>for</strong><br />

decision making. Previously, PRA was conducted by mainly<br />

using the Monte Carlo (MC) simulation, which frequently<br />

requires either empirical or probability distributions of<br />

parameters to simulate the distribution of lifetime daily dose.<br />

The simulation results will be valid if only the input parameters,<br />

data and assumptions are valid. In practice, risk assessors<br />

frequently suffered from insufficient data to fit distributions <strong>for</strong><br />

some parameters, especially concentrations and intake rates, or<br />

even worse spotted data hinder completion of an assessment,<br />

such as a large proportion of residue data below detection limit.<br />

In order to reduce uncertainty due to insufficient data, the<br />

Bayesian statistics Markov chain Monte Carlo (MCMC)<br />

simulation was applied to per<strong>for</strong>m PRA. The limited data<br />

available were used as prior in<strong>for</strong>mation. Markov chain Monte<br />

Carlo simulation was per<strong>for</strong>med with the WinBUG to achieve<br />

the posterior distributions of parameters and health risk. Four<br />

examples will be presented in this meeting; assessment of<br />

lifetime cancer risk <strong>for</strong> N-nitrosodimethylamine (NDMA) in<br />

drinking water (only one sample with detectable NDMA level<br />

out of 50 samples collected), assessment of lifetime cancer risk<br />

<strong>for</strong> aflatoxin B1 in food (only few data greater than regulations<br />

were available), assessment of health risk <strong>for</strong> medical staffs<br />

exposed to cisplatin by using urinary platinum as biomarker to<br />

reconstruct exposures, and assessment of lifetime cancer risk<br />

<strong>for</strong> acrylamide in high-temperature processed foods with high<br />

uncertainty in residue and intake rate data. With limited data<br />

available, the posterior distributions of parameters and health<br />

risk theoretically converge to corresponding representative<br />

distributions <strong>for</strong> the study population so that quality of risk<br />

assessment may be improved without additional investment of<br />

resources to collect data.<br />

P.119 Wu, CY*; Chang, CH; Chung, YC; Chen, CC; Wu, KY;<br />

National Taiwan University; b97310020@ntu.edu.tw<br />

Probabilistic Assessment of Lifetime Cancer <strong>Risk</strong> <strong>for</strong><br />

Acrylamide through Daily Consumption of<br />

High-Temperature Processed Foods in Taiwan with<br />

Bayesian Statistics Markov Chain Monte Carlo Simulation<br />

Acrylamide (AA), a probable carcinogen, present in foods,<br />

especially in carbohydrate-rich food processed at high<br />

temperature. The potential health risk has been of great<br />

concerns due to daily AA intakes which could vary<br />

geographically due to various dietary habits and cooking<br />

process. In order to assess the lifetime cancer risk, a variety of<br />

high-temperature processed foods were collected from several<br />

counties in Taiwan. Totally, AA contents in 300 samples were<br />

analyzed with liquid chromatography tandem mass<br />

spectrometry. Questionnaires were used to collect intakes of<br />

these foods from 132 study subjects. With the limited data on<br />

the AA contents and food intake rates, Bayesian statistics<br />

Markov chain Monte Carlo simulation was to per<strong>for</strong>m<br />

probabilistic assessment of lifetime cancer risk <strong>for</strong> AA through<br />

consumption of high-temperature foods in Taiwan to estimate<br />

the representative distribution of daily AA intake. In this study,<br />

mean intakes doses is 1.655 micro-gram / kg-day <strong>for</strong> the<br />

samples. Use the cancer slope factor (0.51 [mg/kg-day] -1) of<br />

EPA(2010), the mean cancer risk <strong>for</strong> Taiwan population is<br />

8.4410-4. The risk in our study is higher than those of other<br />

studies. This could be attributed to food intake rates probably<br />

overestimated according to surveys from young population.<br />

However, it may be necessary <strong>for</strong> the young study subjects to<br />

reduce the consumption of fried foods.<br />

December 8-11, 2013 - Baltimore, MD

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