CS 2543 Environmental Health Assessment and Management Toi Wan Lung Lo Hin Tung Leu Wing Yan Lam Kok Hang

Local & Overseas

Local News

Dioxins news

Overseas News Dioxins exposure in Vietnam

Characteristic Polychlorinated aromatic compounds Polychlorinated aromatic compounds Metal smelting, molding or burning of chlorine- containing organic chemicals Metal smelting, molding or burning of chlorine- containing organic chemicals Toxic and stable Toxic and stable

Characteristic Lipid soluble Lipid soluble Not easily broken down Not easily broken down Accumulate in fatty tissues Accumulate in fatty tissues Transmit in food chain from Transmit in food chain from plants to animals to humans

Characteristic Different toxicity Different toxicity Basic Structure of PCDDs and PCDFs Basic Structure of PCDDs and PCDFs

Sources of Human Normal Exposure Food intake Food intake Drinking water Drinking water Air inhalation Air inhalation Skin contact Skin contact

Sources of Human Exposure

Potential PCDD/F Sources in Hong Kong Gas-fired power plants Gas-fired power plants Landfill gas combusted in domestic premises Landfill gas combusted in domestic premises

Regulating Agency in Hong Kong Hong Kong Environmental Protection Department Hong Kong Environmental Protection Department Food and Environmental Hygiene Department Food and Environmental Hygiene Department

Tolerable Intake – Recommended Dose Tolerable Intake – Recommended Dose From the Joint Food and Agriculture Organization / World Health Organization Expert Committee on Food Additives (JECFA): From the Joint Food and Agriculture Organization / World Health Organization Expert Committee on Food Additives (JECFA): Provisional Tolerable Monthly Intake (PTMI) of 70 pg/kg/bw/month. (2.33pg/kg/bw/day)

Tolerable Intake – Upper Limit Tolerable Intake – Upper Limit From The World Health Organization (WHO): From The World Health Organization (WHO): tolerable daily intake (TDI) 4 pg TEQ kg -1 (bw) day -1

Assumptions All are healthy All are healthy Common types of fish Common types of fish Use ‘week’ as unit Use ‘week’ as unit Average body structure size Average body structure size 1 cup of fish 1 cup of fish

Uncertainties Age group Age group Sample size Sample size Weight & size of fish Weight & size of fish Sensitivity Sensitivity

Questionnaire Chemical Concentration: pg TEG/g Chemical Concentration: pg TEG/g Contact Rate: 2.62 times / week Contact Rate: 2.62 times / week Exposure Frequency: 136 days / year Exposure Frequency: 136 days / year Exposure Duration: years Exposure Duration: years Body Weight: kg Body Weight: kg Averaging Time: days Averaging Time: days Intake dose = Intake dose = = mg/kg/day = mg/kg/day

Effects to Human Health - Skin Cause Chloracne Cause Chloracne Rush on skin Rush on skin Discolor on skin Discolor on skin Cause excessive body hair Cause excessive body hair Cause cancer Cause cancer

Effects to Human Health - System Affect immune system Affect immune system Affect reproductive function Affect reproductive function Affect endocrine system Affect endocrine system Affect developing nervous system Affect developing nervous system

Effects to Human Health - Baby Dioxin accumulate in fat easily Dioxin accumulate in fat easily Accumulate in women breast Accumulate in women breast Feminization of male Feminization of male

Risk Characterization Short-term Skin lesionsSkin lesions Long-term Impairment of immune systemImpairment of immune system Development of nervous systemDevelopment of nervous system Reproductive functionsReproductive functions Body BurdenBody Burden

Advices for Public Fish species Fish species Fish size Fish size Fish preparation Fish preparation High-risk individuals High-risk individuals Pay attention on news Pay attention on news

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