Chemical Contamination- Heavy Metals Flashcards
Topic-4
what are the 3 heavy metals that cause chemical contamination?
-mercury
-lead
-cadmium
what does the EFSA advise in terms of minimising exposure to mercury? what are 3 foods high in mercury- what group are these part of?
-advise that each country should monitor their fish consumption
-and assess the risk of exceeding the recommended methylmercury levels whilst still getting the health benefits from fish
-swordfish, tuna and shark (large predatorial fish)
what is the programme that the EFSA use to allow consumers to monitor their methylmercury intake? what is the TWI for methylmercury and inorganic mercury?
-Tolerable Weekly Intake- TWI `
-methylmercury is 1.3 micrometers per kilogram of body weight and inorganic mercury is 4 micrometers
what form of mercury is better for the body?
-the organic form- methylmercury
what population would be most vulnerable to a high exposure to methylmercury? what is the result in this in children? (statistic)
-populations where fish is their staple diet
-among these populations between 1.5-17 in every 1000 children show cognitive impairment due to over exposure to methylmercury
According to WHO what are the main risks to public health due to an over exposure to mercury? what are the risks to pregnant women?
-mercury exposure even in small amounts can cause serious health problems especially for pregnant women and developing foetuses
-methylmercury is a neurotoxin which can impair cognitive functions, motor skills and sensory abilities
-chronic exposure can damage the nervous, digestive and immune system, also affecting the lungs and eyes
-methylmercury can cross the placenta in pregnant woman and affect foetal brain development
what is the current advise on fish consumption by the FSA, EFSA and WHO?
-limiting the consumption of fish high in mercury is the most effective way to gain the nutritional benefits of fish which minimising the risks of exposure to mercury
-fish like salmon and sardines should be eaten instead as they are low in mercury
what is the current advise on the limited intake of methylmercury by the FSA, EFSA and WHO?
-EFSA established TWI- tolerable weekly intakes
-protects consumers from the adverse health effects of mercury
-for consumption of methylmercury it is 1.3 micrometers per kilogram of body weight, for lactating and pregnant women this is significantly lower at 0.1
what are 5 ways the consumptions of mercury can be minimised for consumers?
-choose lower mercury fish e.g. salmon
-follow consumption guidelines and TWIs set by the EFSA
-consume a varied diet so ensure that fish is not over relied on as a protein source
-stay informed on scientific research on the FSA website
-support policies that reduce mercury emissions from industrial sources which reduced contamination of fish and waters
what are 5 dietary sources of lead?
-root vegetables e.g. carrots, which absorb lead from contaminated soils
-leafy vegetables
-grains
-tap water
-lead shot game
what is the FSA advise on lead levels?
-there is no safe level of lead consumption so should be reduced as much as possible
-vulnerable groups e.g. pregnant women and children should be especially careful
what is the risk of lead consumption for pregnant women?
-can cause miscarriage, stillbirth and low birth weight
-the body stores lead in teeth and bones where it can accumulate over time
-bone can be remobilised into the blood during pregnancy thus exposing the foetus
what is the risk of lead consumption in children and adults?
-children are particularly vulnerable to the adverse effects of lead, can suffer from neurodevelopmental effects in the brain and nervous system
-maximum levels in milk formula are strictly controlled
-in adults long term exposure can cause CVD, anaemia, HBP and kidney damage
how do the FSA and WHO use regulations to monitor the effects of lead on public health?
-FSA and WHO monitor and regulate lead levels in food and the environment
-set MRLs for lead in food and drinking water
how is public health protected from the toxic effect of lead through reducing environmental contamination?
-emissions are being controlled from industrial sources e.g. smelting, which reduces the amount of lead in the atmosphere
-lead free products are being promoted to use
-lead from industrial processes can settle in soil and is absorbed by plants
-old plumbing systems contain lead which can leech into drinking water
what are 5 ways consumers can reduce their lead exposure?
-wash f+v thoroughly to remove surface level lead
-use cold tap water as hot water will promote the leeching of lead which dissolves into the water
-avoid foods that tend to be higher in lead e.g. root vegetables
-promote a healthy varied diet high in vitamin C as it decreases the bodies ability to absorb lead
-hand hygiene particularly for children who are outside as lead can be in soil
how does the FSA monitor cadmium levels?
-they set MRLs in various food products, based on scientific research
-regularly test food samples to ensure safe limits and identify sources of contamination
-they work with food producers to implement good agricultural practices to minimise cadmium contamination
what are 3 foods that can be high in cadmium? how do these foods absorb the cadmium?
-leafy greens
-rice
-seafood
-they absorb cadmium from contaminated soils and waters
what are the 3 health effects of a high exposure to cadmium?
-kidney damage, cadmium absorption in the body is usually small (5%) however it can accumulate in the kidneys
-can cause renal dysfunctions
-breathing cadmium contaminated air can be linked to lung cancer
-long term exposure can also lead to bone demineralisation, and osteoporosis
how do the FSA and EFSA monitor and regulate levels of cadmium?
-they set MRLs of cadmium in food products to ensure safety
-regular monitoring helps to identify and manage risks
how do good agricultural practices help to ensure safe levels of cadmium?
-reducing the use of phosphate fertilisers which contain cadmium
-soil management procedures can lower cadmium uptake
-farmers can also choose to plant crops in areas with a lower cadmium concentration in the soil
how can food processing and preparation be used to ensure safe levels of cadmium?
-certain processing techniquies can reduce cadmium levels e.g. milling rice
-encouraging consumers to diversify their diets also helps to reduce cadmium exposure from a singular source
how can public awareness on the effects of cadmium help to protect public health?
-FSA can educate the public on the sources
-and ways to minimise exposure
-provide information on safe food choices
how can research help to protect public health against the effects of cadmium?
-supporting research into new methods to reduce cadmium levels helps to protect health
-e.g. developing cadmium resistant crops can help to provide long term solutions
