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Week 11: Heavy metals and radiation - Coggle Diagram
Week 11: Heavy metals and radiation
Mercury
Natural occurring heavy metal
Shiny silvery- white liquid at 25c
Has many route of exposures
Source of exposures
organic
elemental: production of thermometers
clinical signs and symptoms
High dose exposure: mental retardation
lower dosage: neurocognitive deficit(controversial)
chronic exposure
neurological symptoms: generalized weakness, psosis
Acute exposure
Due to vapor inhalation
Cough
Sysnea
Inflammation of gum
Chronic
Neurological symptoms
generalized weakness, psosis
Diagnosis: Usually sample of hair and urine
Prevention
Never vacuum mercury
eat less than 12 oz of mercury fish (salmon)
Avoid skin bleaching cream
Reading: some toxic effects may include kidney problems and increased blood pressure
inorganic: skin bleaching
Route of exposure
Sporadic exposure: Breast milk of exposed mother
Reading All 2020
route of exposure is most commonly by inhalation of air pollutants, consumption of contaminated water, and food, and food source such as vegetable, grains, fish, and shellfish
Podcast: Mercury in Seafood
It is advised to eat low mercury fish rather than no fish
pregnant women should be aware of that
women and men at any age should be aware of mercury as well.
Mass exposure: eg:Minamata Bay in Japan. contaminated fish
Podcast: Mercury in Seafood
Seafood contain a lot of mercury
usually due to natural and human made mercury dumped in the ocean
eduction of mercury emission from chemical plants and other industrial sources is what can help in the future.
Week 12: Endocrine disruptors
natural chemicals and man-made chemicals interfere with the body's hormone called endocrine system.
they are linked with developmental, reprodructive, brain, immune system
Some of them are very difficult to break down in the environment
examples of endocrine disruptors
Dioxins: paper bleaching
Bisphenol: epoxy resins
Perchlorate: in fireworks
Phthalates: children's toys
Phytoestrogens: soy milk
Triclosan: in body wash
2 more items...
Podcast Gardening
urban areas have many potential sources of contamination
Gardening is safe but there are also contaminated areas.
Gardeners can eliminate most risk for fruits in crops with smooth skin like peppers, tomatoes, and eggplants
it is more challenging for root vegetable like carrots
soil testing is a way to determine the level of contamination of soil.
Reading Sall 2020
water pollution by heavy metals has many anthropogenic origins (human origins)
They occur naturally due to volcanoes, erosions, infiltrations etc.
Arsenic
organic: organic arsenical pesticides are toxic
elemental: used as alloy and semiconductor industry
Inorganic: Trivalent and pentavalent (for insecticides and poison)
Routes of exposure
Mostly absorbed through ingestion
Not absorbable through intact skin
May be transported through placenta.
Bioavailability Podcast:
Bioavailability: the amount of the amount of a contaminant or any food item. How much we ingest and how much food item is contained in our body
Children are likely to be exposed to heavy metals because of their habit to play in dirt and put their fingers in their mouths.
sources of exposure
Well water
Anthropogenic
Incinerator
Fish
Rice
Pesticides
symptoms Acute/ High dose
Emesis
abdominal cramping
Diarrhea
Multi-organ failure
Lower doses: hypotension, congestive heart failure etc.
Symptoms chronic exposure
low grade bone marrow deoression
fatigue
neurologic dysfunction
diagnosis
excreted through kidney
spot urine recommended
24h urine test
Treatment
succimer
Dimercapol*
Prevention
Drinking water
Avoid contaminated water or soil in agriculture
avoid old wooden cribs.
Radiation
The gray
Long term effect of diagnostic radiation in children
Breast cancer
Leukemia
Tuberculosis
cardiac cath
scoliosis
exposure
sickness when body receives 1 gy
no survival after 6 gy
nausea, vomiting, diarrhea, headache, fever
late symptoms: dizziness, disorientation, fatigue, weakness, hair loss, blood emesis and stool, poor wound healing etc.
diagnosis
Blood test
dosimeter
Treatment
potassium lodine
external
decontaminaton
supportive care
Prussian blue
The sievert
Week 13 Vector borne and Zoonotic diseases
Vector borne diseases.
Epi triad has 3 component: agent, host, and environment.
agent are typically viruses, bacteria, parasites.
e.g Rhabdoviruses--> Rabies
environment: must be suitable for agent survival
Direct transmission: human host exposed to agent through direct contact with an infected animal eg: Chagas diseases, bite of animal
indirect transmission: human host exposed to agent through another animal or other medium: vector borne
Host: agents can have multiple hosts depending on life cycle
eg. Malaria, host is mosquito anopheles.
zoonotic
Disease spread between humans and animals
emerging: outbreakeaks of new diseases (Covid-19)
Why?
deforestation
Loss of biodiversity
Environmental degradation
urbanization
growth of population
spillover events: initial event when a disease is transmitted from an animal to a human
e.g:
HIV: Human exposed through infected blood of non-human primate.
Yellow fever.
Reading:
TB represents a risk factor for HIV
Podcast TPWKY yellow fever
yellow fever is a RNA virus like influenza
transmitted by mosquito= vector borne disease
by a female mosquito like malaria
It traces its otginins back to Africa
Got to America by slave trades
Reading Plowright 2017
some examples of outbreaks include Ebola virus, Influenza A virus, Corona, etc.
Route of transmission from reservoir hosts: Excretion, slaughter, vector borne
Reading Zoonotic/ Global health
collaboration across sectors are essential for quantifying the burden of zoonotic disease.
Reading Belay 2017
Mitigating the impact of endemic and emerging zoonotic diseases of public health importance requires multisec- toral collaboration and interdisciplinary partnerships.
Countries that lack a well-functioning coordina- tion mechanism could fail to rapidly detect and effectively respond to emerging health threats, which could spread to other countries and threaten global health security.
Re-emerging: reappearance of disease.
Belay 2017
prevention of zoonotic diseases involve routine immunization programs, large scale culling, and effective biosecurity