Environmental disease Flashcards
Quite irrelevant content ngl
What are environmental diseases?
- Ill health associated with where people live and what they ingest
- Physical agents we are exposed to
- Exogenous substances we ingest
- Exogenous substances we inhale
- Surrounding
PHYSICAL AGENTS:
1- UV radiation is classed as what type of carcinogen?
2- How can you protect yourself against UV?
3- What 3 main organs are affected by UV?
1- class 1
2- Sunscreen, Sunglasses with UV filter, avoidance: clothing
3-
Skin: Cutaneous malignant melanoma, squamous cell carcinoma and basal cell carcinoma
Lips: positive association with cancer of the lip
Eyes: positive association with conjunctival squamous cell carcinoma and ocular melanoma , cataract
1- What is the prevalence of melanoma?
2- Why do black people tend to get a diagnosis much later compared to white people?
1- More prevalent in people with white skin .. melanin offers some protection
2- Contributing factors:
- Lack of education on melanoma targeted at non-white people – low awareness and self-screening
- Socio-economic disparities (e.g. uninsured patient or those on Medicaid)
- Lower index of suspicion from patients and clinicians
- Increased prevalence of acral and mucosal melanoma that tend to be more aggressive, more challenging to diagnose early and don’t respond as well to current therapy
- Melanoma in people with darker skin one is under-representation in research, educational literature and training programme.
- Recommendation on sun-protective practices for non-white people is unclear
1- Exposure to UVB is necessary, why?
1- production of vitamin D3 in the skin, a precursor to 80-90% of Vitamin D
> Regulates intestinal Ca2+ and PO4- absorption, necessary for bone homeostasis
» Insufficient Vitamin D leads to rickets in children and osteomalacia in adults
Melanin absorbs UVB what does this mean for black people?
- People with darker skin have lower vitamin D levels
- Conversion of 7-dehydroxycholesterol to pre-vitamin D3 is not as effective
What is the adequate vitamin d?
What sources contain vitamin d?
- Vitamin D > 50 nmol/L
- Oily fish, red meat, egg yolks, supplements, some fortified cereals, fat spreads and all formula milk for infants and toddlers
1- Heatwaves vs snow, which is more detrimental?
2- Who is more affected by heatwaves?
3- Who is at risk of extreme weather?
1- Low temperatures more risky
2- Excess deaths from other diseases such as respiratory diseases and cancer due to high-night temperatures.
3- Affects vulnerable groups (children, older adults, pregnant individuals, people with chronic disease)
= Increased pressure on healthcare systems
Lead is an exogenous factor, how can it cause disease?
> Chronic exposure to lower doses of Lead affects:
- Haem synthesis -> microcytic, hypochromic anemia
- Neurobehavioral development -> linked with delayed cognitive development and hyperactivity
- Reduced production of the active form of vitamin D
- Reduced growth
Children are especially at risk (even before birth!)
Bisphenol-A (BPA) is an exogenous factor how can it cause disease?
- Disrupts the neuroendocrine regulation systems, i.e. hypothalamus – pituitary – gonad / adrenal / thyroid axes
> Estrogen receptor agonist, thyroid hormone receptor antagonist, low binding to SHBP
= BANNED as Concern that when plastic is degrading, BPA may leach in the food / drink it is packaging
1- What are the basics to an adequate diet?
2- What is malnutrition?
3- Why is malnutrition as issue in uk?
1- Energy in the form of carbohydrates, proteins and fats
- Essential (and non essential) amino acids and fatty acids
- Vitamins and minerals
2- Malnutrition: deficiency, excess or imbalance of a wide range of nutrients resulting in a measurable adverse effect on body composition, function and clinical outcom
3-
- Poverty, access to low quality food, age, low education, chronic and acute illnesses (incl. chronic alcoholism/drug), dietary restrictions, total parenteral nutrition, etc
How can deficient in vitamin B12 cause disease?
- Can cause megaloblastic anaemia, bone marrow changes, neuropsychiatric symptoms, peripheral neuropathy, subacute spinal cord degeneration
> Causes:
- Low dietary intake (vegetarian / vegan diet)
- Defective absorption:
> loss of relevant sections of the GI tract: gastrectomy, ileum resection
> Autoimmune gastritis that impairs production of Intrinsic factor (Pernicious anaemia)
> Congenital / inherited mutations (rare), parasite infestation - Drugs (alcohol, PPI, H2 receptor agonists, metformin, etc)
What does vitamin B12 deficiency cause in RBC? What is the mechanism behind this?
- Macrocytic RBC + fewer + Containing lots of hb
- Anisocytic -(RBC are of unequal sizes)
- Poikilocytic - (RBC abnormal variation in the shape of red blood cells)
- Large hyperhsegmented neutrophils
> Methymalonyl-coA isomerization to succinyl coA by enzyme requiring vitamin B12 as co-factor
- Methylmalonate and propionate accumulation could cause abnormal lipids to be formed and incorporated into neuronal cell membranes or myelin sheath
Radon is an exogenous factor how can it cause disease?
- Outdoor expose is very low – the potential issue comes from indoor exposure as concentration in indoor air can be relatively higher
- Highly ionizing -> damage to DNA in lung cell mucosa exposed to inhaled gas particles
- Radon exposure is the greatest single contributor to radiation exposure in the UK
what outdoor air pollution cause disease?
What are sources of outdoor air pollution?
- Natural sources ( volcanoes, wildfires, wind, sand storms, plant decay)
- Anthropogenic sources (combustion of fossil fuels)
PM,NO,SO2, Ammonia, VOCs
