chapter 9 environmental nutritional disorders Flashcards
The Global Burden of Disease (GBD) measures what? by what unit?
estimates the burden imposed by environmental disease including communicable and nutritional diseases.
-applying the DALY metric (disability adjusted life year) which is a sum of years of life lost due to premature mortality and years of life lost to disability in a population
___ is the single leading cause of health loss (defined as morbidity and premature death)
undernutrition
on a worldwide basis there was a dramatic increase in mortality due to _____
HIV/AIDS and associated infections
___ and ___ are the leading cause of death in developed countries
ischemic heart disease, and cerebrovascular disease (CVD)
-main risk factors associated with loss of healthy life: smoking, HTN, obesity, high CHO, alcohol abuse
in developing countries 5 out of 10 leading causes of death are
infectious disease
in the postnatal period, about 50% of all deaths in children younger than 5 are attributed to what 3 conditions? are they preventable or not?
pneumonia, diarrheal disease, malaria
all preventable
Please Make Developments
categories of emerging (recently increased or could reasonablely increase in the near future) infectious disease
- dz caused by newly evolved strains/organisms (resistant drugs)
- dz caused by pathogen “jumping” into human species
(HIV) - dz always present but have shown recent increase in incidence ( dengue fever due to warming climate)
**risk to spread to southern US
principal culprit in global warming
rising atmospheric level of greenhouse gases
- particularly CO2 from burning fossil fuels, ozone, and methane
- these gases with water vapor produce green house effect by absorbing and re-emmiting infrared energy radiated from earth surface that would normally be lost in space
-increases also from deforestation and decrease in attendant decrease in carbon fixation by plants
health impacts of climate change will depend on what 3 things
- extent/rapidability
- nature/ severity of consequences
- our ability to mitigate the damage
the negative impact associated with climate change is the increased incidence of what diseases
- cardiovascular, cerebrovascular, respiratory (worsened by heat waves and air pollution)
- gastroenteritis, cholera, food/waterborne dz (contamination following weather disasters)
- vector-borne infectious diesase like malaria and dengue fever (increased temp, crop failure, extreme weather)
- malnutrition (disrupted crop production)
define toxicology
distribution, effects, and mechanism of action of toxic agents
-studies effects of physical agents such radiation and heat
“ science of poisons”
define poison
- *strictly dependent on dosage
- not straightforward
define xenobiotic
exogenous chemicals in the environment (air, water, food, soil) that may be absorbed into the body (inhalation, ingestion, skin contact)
how do most drugs and solvents enter cells
-most solvents and drugs are lipophilic. transport in the blood is facilitated by lipoproteins. lipophilic nature allows transport through the plasma membrane
how do solvents, drugs, and xenobiotics affect cells after entering them
most are metabolized to a inactive water-soluble product (detoxification) or activated to form toxic metabolites
what are the 2 phases associated with xenobiotics metabolism into nontoxic products or active toxic compounds. what is the most important enzyme associated
phase 1: chemical undergo hydrolysis, oxidation, or reduction
phase 2: products of phase 1 metabolized into water soluble compounds via glucuronidation, sulfation, methylation, and conjugation with glutathione.
*enzymes that catalyze biottransformation of xenobiotics and drugs = drug metabolizing enzymes
- Cyt P-450 = most important phase 1 catalyst located mainly in ER of liver (also skin, lungs, GI, etc)
- heme containing enzyme
- may produce ROS as byproduct in both detoxifying and toxic metabolite reactions
- participate in metabolism of: acetaminophen, barbiturates, warfarin, anticonvulsants, and alcohol
- fasting or starvation can decrease CYP activity
- variation of activity among individuals
air pollution is especially hazardous to people with ____
preexisting pulmonary or cardiac disease
outdoor air pollutants
ozone, nitrogen dioxide, sulfur dioxide, acid aerosols, particulates
***O -S N A P
how is good ozone produced and what is its function
- interaction of UV radiation and Oxygen in the stratosphere and naturally accumulates 10-30 miles above earth surface
- this layer protects life on earth by absorbing UV radiation emitted by the sun
- can be destroyed by air pollutants
what is bad ozone and what is its effects
“ground level ozone” or ozone that accumulates in the lower atmosphere instead of the stratosphere = most dangerous air pollutant
- formed by rxn of nitrogen oxides and volatile organic compounds in presence of sunlight
- ozone toxicity is mediated by free radical production that damage epithelial cells along respiratory tract and type 1 alveolar cells
- healthy individuals= upper respiratory tract inflammation and mild symptoms of decreased lung function, chest discomfort, increased airway reactivity, and lung inflammation
- athletes, outdoor workers, asthmatics or those with emphysema = decreased exercise capacity, increased hospitalizations
what is the effects of the outdoor air pollutant sulfur dioxide and how is it made
- produced by plants burning coal and oil, copper smelting, and paper mill by product
- combines with ozone = witches brew
- converted into sulfuric acid or sulfur trioxide = nose/throat burning, dyspnea, asthma attacks
- increased respiratory symptpms, mortality, hospitalizations, and decreases lung function
what is “soot”
particulate matter that is a known outdoor air pollutant
-imp cause of mortality and morbidity related to pulmonary inflammation and secondary cardiovascular effects
-ultrafine particles
-readily inhaled in alveoli releasing lots of inflammatory mediators
(> 10 micrometers = less damaging bc removed in nose or trapped in mucous)
*only air pollutant that increases risk of attacks with heart disease patients
a non irritating colorless tasteless odorless gas produced when there is incomplete oxidation of hydrocarbons that kills its victims by CNS depression and widespread ischemic change.
carbon monoxide
- 200x greater infinity for O2 than Hgb
- generalized cherry-red color of skin and mucous membranes
what are the effects of carbon monoxide poisoning
- acute toxicity in 5 minutes and can lead to coma or death
- affects the basal ganglia and lenticular nuclei via ischemic changes
- long exposure and survival = brain edematous. punctate hemorrhage, hypoxia-induced neuronal changes
- if pt recovers = impaired memory, vision, hearing, speech
indoor air pollutant
wood smoke, bioaersols, radon, formaldehyde, sick building syndrome (multiple indoor pollutants + poor ventilation)
radioactive gas derived from uranium widely present in soil and in homes and can cause lung cancer in long term high exposure
radon
what are the metals associated as environmental pollutants
lead, mercury, arsenic, cadmium
*CALM
what metal is readily absorbed and binds to sulfhydrol groups in proteins and affects calcium metabolism. and what major effects does it have?
LEAD
- effects lead to hematologic, skeletal, neurologic, gastrointestinal, and renal toxicities
- most absorbed lead is incorporated into bones and developing teeth, and competes with calcium, and half life of 20-30 years in bone
- low levels = neuro impairments (drop in IQ), behavioral problems, hyperactivity, blindness. toxcity affects brain development
- in adults mainly causes peripheral neuropathies = wrist drop (affected extenosors) and foot drop ( perineal muscle paralysis)
- encephalopathy in kids
- LEAD LINES in gums and radio dense in bone X-rays
- = heme deficiency and HYPOCHROMIC MICROCYTIC ANEMIA with basophilic stippling and ring sideroblasts (iron laden mitochondria)
- lead colic = severe poorly localized ab pain
- possible renal failure
classification of microcytic hypo chromic anemia
MCV <80 [volume]
MCH < 27 [Hgb]
describe mercury toxicity
-binds to sulhydryl groups and damages CNS of developing brains and kidneys
-sources: contaminated fish, mercury vapors, and in dental amalgams
= minamata dz = cerebral palsy, deafness, blindness, retardation,
**major CNS defects in children exposed in utero
which metals bind to sulfhydryl groups in proteins
lead and mercury
effects of arsenic poisoning
- interferes with cell metabolism
- affects GI, nervous system, skin, heart
- sources: naturally in soil and water, wood preservatives, herbicides, herbal medicines
- 2-8 wks post exposure, sensorimotor neuropathy, parathesisa,, numbness pain (neuro signs)
- chronic exposure - skin changes (hyperpigmentation and hyperkeratosis) , respiratory disease
- increased cancer risk of lungs, bladder, skin (palms and soles)
effects of cadmium toxicity
- toxic to kidneys and lungs
- uncertain mechanism that causes ROS production
- source: nickel-cadmium batteries, soil and plants contamination, MOST IMP = food
- alveolar epithelial cell necrosis = obstructive lung dz
- renal tubular damage –> end-stage renal disease
- skeletal abnormalities associated with calcium loss
- itai-itai = postmenopausal dz, combo of osteoporosis and osteomalacia associated with renal dz
- increased risk of lung cancer
what are MEES lines and where are they seen
-hyperkeratonisis which is a sign of arsenic poisoning
6 important occupational health exposures
- formaldehyde - respiratory irritation
- ammonia- respiratory irritation
- asbestos- lung cancer
- arsenic -lung cancer
- uranium -lung cancer
- benzene - leukemia
occupational exposure of rubber workers to the organic solvent benzene and 1,3 butadiene increases risk of
leukemia
-dose dependent marrow aplasia and increased risk of acute myeloid leukemia
what organochlorines disrupt hormone balance by being anti-estrogenic and anti-androgenic
DDT and PCB
what occupational exposures are linked with increase in lung cancer
radon, asbestos, silica, bis ether, nickel, arsenic, chromium, mustard gas, uranium
BAR CAN SUM
what occupational exposures are linked with increase in fibrosis of respiratory system
silica, asbestos, cobalt
SAC
which metal exposure can lead to ataxic gait
mercury
vinyl chloride exposure affects what
GI tract –> liver angiosarcoma
what metal exposure leads to chronic obstructive lung disease
cadmium
organic solvents such as chloroform and carbon tetrachloride have what effects
CNS depression, comma, dizziness, confusion
____ most potent carcinogens released during combustion of fossil fuels (coal and gas), and industrial exposure is linked to lung and bladder cancer. is present in soot which was said to be cause of scrotal cancer in chimney sweeps
polycyclic hydrocarbons
what causes folliculitis and dermatosis disorder known as chloracne (acne, cysts, hyperpigmentation, hyperkeratinosis) and liver and CNS problems
PCB and dioxins
what causes chronic nonneoplastic lung dz called pneumoconiosis
-inhalation of mineral dusts:
coal dust, silica, asbestos beryllium
(CABS)
what leads to mesothelioma , black lung and increases risk of cancer
asbestos
what are ferruginous bodies
asbestos fibers coated in iron and calcium ( seen in vascular mesenchymal tumors)
Blue stains on histo slide
___ is a potential endocrine disruptor linked to heart disease in adults and endocrine effects in infants
BPA
what is the leading exogenous cause of cancer and 90% of all lung cancers
tabacco
how to find pack years of smokers
avg number of packs smoke/day x numbers of years smoking
cessation of smoking greatly decreases risk of mortality and death by CVD dz in __ years. lung cancer mortality decreases ___ in ___ years, but the excess risk persists for 30
5 years
21% in 5 years
___ is not a direct cause of tobacco related dz (even though found in tobacco leaves) but is strongly addictive
nicotine
which country is the worlds largest producer and consumer of cigarettes
CHINA