Environmental and Nutritional Disorders Flashcards
Global Disease Burden (GDB)
estimates the burden imposed by environmental disease, including those caused by communicable and nutritional diseases
Disability adjusted life year (DALY)
sum of years of life LOST due to premature mortality and disability in a population
What happened to the GDB from 1990-2010? Cause?
increase in mortality due to HIV/AIDS
What is the leading global cause of health loss?
undernutrition
What is the leading cause of death in developed countries?
ischemic heart disease and cerebral vasculature disease
What are 5 of 10 leading causes of death in developing countries?
Infectious disease
50% of all deaths in kids younger than 5 years are attributed to what 3 diseases?
pneumonia, diarrheal disease, and malaria
What are the categories of emerging infectious diseases?
newly evolved strains or organisms- multi-drug resistant TB
pathogens endemic to other species that recently “jumped” to human population-HIV
pathogens that have been present in human population, but increase in incidence- dengue fever due to warming
What will be the preeminent global cause of environmental disease if no action is taken?
climate change
What will the health impacts of climate change depend on?
extent and rapidity, nature and severity of the consequences, and our ability to mitigate the damage
Affects of heatwaves and air pollution in disease
Cardiovascular, cerebrovascular, and respiratory diseases worsten
Contamination from floods and disruption of clean water supplies causes
Gastroenteritis, cholera, and other food-borne and waterborne infectious diseases
Examples and causes of vector-borne infectious diseases
malaria, Dengue fever; increased temperature, crop failures, and more extreme weather variations
Disrupted crop production causes what?
malnutrition
Toxicology
distribution, effects, and mechanisms of action of toxic agents
How many pounds of toxic chemicals and unrecognized carcinogens are released per year in the US?
4 billion pounds; 72 million lbs carcinogens
Xenobiotics
exogenous chemicals in the environment (air, water, food, soil) that may be absorbed into the body (inhaled, ingested, skin contact)
Lipophilic
can transport and penetrate through the basement membrane; most solvents and drugs
Detoxification
when solvents, drugs, and xenobiotics are metabolized to an inactive water-soluble product
What is the other outcome for solvents, drugs, and xenobiotics besides detox?
activated to form toxic metabolites
Phase 1 reaction of xenobiotics
hydrolysis, reduction, oxidation
Phase 2 reaction of xenobiotics
glucoronidation, sulfation, methylation, and conjugation
Cytochrome P-450
located in ER of the liver, also present in skin, lungs, GI mucosa
catalyzes reactions that either detoxify xenobiotics or convert them into active compounds that cause cell injury
What byproduct can P-450 produce?
ROS–>cell damage
Is the CYP activity between people the same?
No, great variation
What decreases the action of CYP?
fasting and starvation
Who is more susceptible to air pollution?
persons with preexisting pulmonary or cardiac disease
What are the major causes of morbidity and mortality when it comes to pollution?
airborne microorganisms
What are there limits on regarding air pollution?
sulfur dioxide, carbon monoxide, ozone, nitrogen dioxide, lead, and particulate matter
Where is smog the highest?
Beijing, LA, Houston, Cairo, New Delhi, Mexico City, and Sau Paulo
Ground level ozone toxicity
mediated free radicals; injure respiratory tract epithelial cells and type I alveolar cells, releasing inflammatory mediators–>mild symptoms
Who is more affected by ozone toxicity?
people with asthma or emphysema
Sulfur dioxide toxicity
combines with ozone and particulate matter–>witches brew
How is sulfur dioxide toxic made?
power plants burning fossil fuels, copper smelting, and byproduct of paper mills
What symptoms does sulfuric acid and sulfuric trioxide cause?
burning sensation in nose and throat, difficulty breathing, and asthma attacks
Particulate matter (soot)
pulmonary inflammation and secondary CV effects
What are the most harmful particulate matters?
fine or ultrafine particles less than 10 micrometers in diameter
What happens to particulate matter over 10 micrometers?
removed in the nose or trapped by the mucociliary epithelium of the airway
Carbon monoxide
nonirritating, colorless, tasteless, odorless gas produced when there is incomplete oxidation of the hydrocarbons
Chronic carbon monoxide poisoning
working in tunnels, underground garages, and in highway toll booths with high exposure to car fumes
Acute carbon monoxide toxicity
in a small, closed garage, the average running car can produce sufficient CO to induce coma or death within 5 minutes
How does CO kill?
inducing CNS depression, widespread ischemic changes
basal ganglia and lenticular nuclei
If death occurs rapidly, NO morphological changes
Longer survival with CO poisoning- what does brain look like?
May be slightly edematous, with punctate hemorrhages and hypoxia-induced neuronal changes
Symptoms if pt survives CO poisoning
impaired memory, vision, hearing, and speech
Pathophysiology of CO poisoning
Hb has a 200-fold greater affinity for CO than O; systemic hypoxia–>20-30% saturated with CO
unconsciousness and death- 60-70% saturation in less than 5 minutes
Appearance of someone with CO poisoning
cherry red color of the skin and mucous membranes
Wood smoke
polycyclic hydrocarbons are carcinogens
Bioaerosols
Legionnaires disease, viral pneumonia, pet dander, fungi, molds
Radon
radioactive gas derived from uranium; increased lung cancer risk
Formaldehyde
building materials, poorly ventilated trailers following disasters; carcinogen
Sick building syndrome
indoor pollutants, poor ventilation; flood-hit buildings
damp homes–>molds like aspergillus and penicilium–>allergic rhinitis and recurrent sinitus
Symptoms of sick building syndrome
headache, chest infection, chest congestion, congestion of nose and around eyes
Why are fine or ultrafine particles more dangerous?
readily inhaled into the alveoli, releasing a number of inflammatory mediators
Lead
readily absorbed metal that binds to sulfhydryl groups in proteins and interferes with Ca2+ metabolism
What effects do lead lead to?
hematologic, skeletal, neurologic, gastrointestinal, and renal toxicities
How can you get lead poisoning?
flaking lead paint and soil- kids
occupational exposure
Where is most of the absorbed lead incorporated in the body?
bone and developing teeth, competes with calcium; stays in bones 20-30 years
Effects of low levels of lead
subtle deficits in intellect, behavioral problems, hyperactivity, poor organization skills in kids–>brain damage
Brain damage with lead poisoning
sensory, motor, intellectual, and psychological impairments; decreased IQ, learning disabilities, retarded psychomotor development, blindness
Brain damage with severe lead poisoning
psychoses, seizures, and coma
How does Pb toxicity in a mother affect a fetus?
impair brain development in prenatal infant
Adult peripheral neuropathies due to lead
CNS disturbances Wrist drop (extensors), followed by paralysis of the peroneal muscles (foot drop)
Lead lines
radiodense deposits in metaphyses (interferes with remodeling of cartilage); also lead lines in the gums
Lead and its affects on blood
heme deficit–>hypochromic microcytic anemia, basophilic stippling, and ring sideroblasts (iron-laden mitochondria)
Lead colic
extremely severe, poorly localized abdominal pain
Renal affects of lead
proximal tubule damage, chronic damage–>interstitial fibrosis and possible renal failure
Microcytic hypochromic anemia
MCV < 80 fL
MCH < 27 pg
due to lead poisoning
Ringed sideroblast
associated with sideroblastic anemia, due to excess iron in mitochondria
What size should RBCs be?
The neutrophil of a small lymphocyte
Mercury
binds to sulfhydryl groups, damage CNS and kidney
Main source of mercury
contaminated fish (methyl mercury), mercury vapors from metallic mercury in dental amalgams
Minamata disease
cerebral palsy, deafness, blindness, MR, and major CNS defects in children exposed to mercury in utero
Arsenic
interfere with cell metabolism–> toxicities most prominent in the GI tract, nervous system, skin and heart (Borgia and Medici poisonings)
Where can arsenic be found?
soil and water (natural); wood preservatives, herbicides, herbal medicines
Large quantities of arsenic ingested cause toxicity where?
GI, cardiovascular, and CNS
2-8 weeks postexposure of arsenic
sensorimotor neuropathy, paresthesias, numbness, pain
Chronic skin changes due to arsenic
hyperpigmentation and hyperkeratosis
Arsenic leads to increased risk for cancers where?
lungs, bladder, and skin (palms and soles)
Cadmium
toxic to kidney and lungs via uncertain mechanisms that may involve increased ROS
Source of cadmium
nickel-cadmium batteries, soil, plants= food
What diseases does cadmium cause?
obstructive lung disease, renal tubular damage, skeletal abnormalities associated with calcium loss
increased risk of lung cancer
Itai-Itai
ouch-ouch; Japan; osteoporosis and osteomalacia with renal disease
Toxicants that can cause lung cancer
radon, asbestos, silica, nickel, arsenic, chromium, mustard gas, uranium
Toxicants that can cause fibrosis
silica, asbestos, cobalt
Benzene causes what?
leukemia
Vinyl chloride causes what?
liver angiosarcoma
Examples of organic solvents that are occupational health risks
chloroform and carbon tetrachloride–>CNS depression and coma
Exposure to benzene and 1,3-butadiene causes increased risk of what? Who is affected?
leukemia; rubber workers
What does benzene and 1,3-butadiene do to the body?
marrow aplasia and increased risk of acute myeloid leukemia
Polycyclic hydrocarbons
from combustion of fossil fuels; scrotal cancers in chimney sweeps
most potent carcinogens–>lung and bladder cancer
Organochlorines
synthetic lipophilic products that resist degradation
What is an important organochlorine?
DDT used in pesticides
PCBs and dioxin are nonpesticide organochlorines
Dioxins and PCBs
folliculitis and dermatosis- chloracne
abnormalities in liver and CNS
Chloracne
due to dioxins and PCBs
acne, cyst formation, hyperpigmentation and hyperkeratosis, face and behind ears
Mineral dusts
coal dust, silica, asbestos, beryllium–>pneumonconioses
Asbestos
mineral dust–>mesothelioma, black dust
Ferruginous bodies
due to mineral dusts–> asbestos fibers coated in iron
appear blue
Vinyl chloride
angiosarcomas in liver
Bisphenol A (BPA)
line almost all food bottles and cans
potential endocrine disruptor
Tobacco
leading exogenous cause of human cancers, 90% of lung cancers
Is tobacco use dose dependent?
Yes, pack years