Week 11: Heavy metals and radiation

Mercury

  • Natural occurring heavy metal
  • Shiny silvery- white liquid at 25c
  • Has many route of exposures

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.

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

Source of exposures

organic

elemental: production of thermometers

inorganic: skin bleaching

Treatment

  • succimer
  • Dimercapol*

Prevention

  • Drinking water
  • Avoid contaminated water or soil in agriculture
  • avoid old wooden cribs.

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

Route of exposure

Sporadic exposure: Breast milk of exposed mother

Radiation

  • The gray

The sievert

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

Reading Sall 2020

  • water pollution by heavy metals has many anthropogenic origins (human origins)
  • They occur naturally due to volcanoes, erosions, infiltrations etc.

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

Reading: some toxic effects may include kidney problems and increased blood pressure

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.

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

routes of exposure

  • Inhalation: Pesticides applied
  • ingestion: food and beverage
  • direct contact: skin

NIEHS research found that endocrine disrupting chemicals

  • reduces immunity in children
  • increases risks of diabetes and metabolic disorsers
  • premature breast develpmner in girls and abnormal breast development in boys.

Ted Talk

  • estrogen increase in human create tumors. studies show that


  • African American are 11 out 13 times more likely to experience cancer

Ted Talks

  • atrazine in drinking water is associated with breast cancer

EDS Reading.

  • example of pesticides DDT
  • ichlorodiphenyltrichloroethane

EDS Reading
Women who were exposed in utero exhibit a higher incidence of breast cancer and clear cell carcinoma of the vagina, in parallel to studies in mice

Podcast Plastic as EDS

  • synthetic Estrogen can have affect of body mass during puberty

Week 13 Vector borne and Zoonotic diseases

Vector borne diseases.

Epi triad has 3 component: agent, host, and environment.

zoonotic

Disease spread between humans and animals

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.

emerging: outbreakeaks of new diseases (Covid-19)

Re-emerging: reappearance of disease.

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 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:
TB represents a risk factor for HIV

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.

Belay 2017

  • prevention of zoonotic diseases involve routine immunization programs, large scale culling, and effective biosecurity

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

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.