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| {{Variable|Exposure-response functions}}
| | #REDIRECT [[ERF of methylmercury]] |
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| == Scope ==
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| '''[[ERF]] of methyl mercury on intelligence quotient''' describes the quantitative relationship between exposure to (prenatal) methyl mercury exposure and intelligence quotient (IQ) score (in children).
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| == Definition ==
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| === Causality ===
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| === Data ===
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| '''Actual content'''
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| Prenatal MeHg exposure sufficient to increase the concentration of mercury in maternal hair at parturition by 1 ug/g decreases IQ by 0.7 points (min and max 0 and 1.5, respectively).
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| '''Narrative description'''
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| Every 1 ug/g of methylmercury in mothers hair decreases IQ of a child by 0.7 points. Study by Cohen et al<ref name="cohenMMVa">Methyl mercury: Cohen et al 2005a</ref> finds that prenatal MeHg exposure sufficient to increase the concentration of mercury in maternal hair at parturition by 1 ug/g decreases IQ by 0.7 points. The paper identifies important sources of uncertainty influencing this estimate, concluding that the plausible range of values for this loss is 0 to 1.5 IQ points.<ref name="cohenMMVa"/>
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| A triangular distribution with parameters: min = 0, mode = 0.7 and max = 1.5 was created. Distribution by author judgement. {{disclink|Author judgement about the chosen distribution}}
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| This variable includes conversion from mercury intake to mercury concentration in hair. Firstly, WHO(1990) suggests the use of a single-compartment model, through which the steady-state Hg concentration in blood (C) in ug/l is related to the average daily dietary intake (d) in ug of Hg, as follows: C = 0.95 * d. Secondly, blood mercury was converted to total hair mercury using a 1:250 ratio (New Zealand and Seychilles Island studies) and an assumption of equivalent maternal and cord levels.<ref>Methyl mercury: Bidone_et_al(2004)</ref> {{disclink|Toxicologicy of methylmercury}}
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| === Formula ===
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| Analytica_id:
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| <Anacode>triangular(-1.5,-0.7,0)*Blood_to_hair</Anacode>
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| == Unit ==
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| IQ points / 1 ug/g increase in maternal hair
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| == Result ==
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| {{resultlink}}
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| ==References==
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| <references/>
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