Hertz: Environmental Flashcards
how to measure environmental effects on global disease burden
DALY (disability-adjusted life year)
slim man’s disease
losing weight
can’t breathe well
diarrhea
= HIV/ AIDS
Health effects of climate change
Cardiovascular, cerebrovascular, and respiratory diseases, all of which will be worsened by heat waves and air pollution
Gastroenteritis, cholera, and other foodborne and waterborne infectious diseases, caused by contamination as a consequence of floods and disruption of clean water supplies and sewage treatment, after heavy rains and other environmental disasters
Vector-borne infectious diseases, such as malaria and dengue fever, due to changes in vector number and geographic distribution related to increased temperatures, crop failures, and more extreme weather variation (e.g., more frequent and severe El Niño events)
Malnutrition, caused by changes in local climate that disrupt crop production. Such changes are anticipated to be most severe in tropical locations, in which average temperatures may already be near or above crop tolerance levels; it is estimated that by 2080, agricultural productivity may decline by 10% to 25% in some developing countries as a consequence of climate change.
poison dosage
when 50% of the population dies, it’s the LD50 toxicity
The P-450 system
catalyzes reactions that either detoxify xenobiotics or, less commonly, convert xenobiotics into active compounds that cause cellular injury
particulate matter
(known as “soot) is a particularly important cause of morbidity and mortality related to pulmonary inflammation and secondary cardiovascular effects.
Wood smoke
containing various oxides of nitrogen and carbon particulates, is an irritant that may predispose to lung infections and may contain polycyclic hydrocarbons, important carcinogens.
can contribute to indoor air pollution
Bioaerosols
range from microbiologic agents capable of causing infectious diseases such as Legionnaires disease, viral pneumonia, and the common cold, to less threatening but nonetheless distressing allergens derived from pet dander, dust mites, and fungi and molds responsible for rhinitis, eye irritation, and asthma.
Radon
a radioactive gas derived from uranium widely present in soil and in homes, can cause lung cancer in uranium miners. However, it does not seem that low-level chronic exposures in the home increase lung cancer risk, at least for nonsmokers
Exposure to formaldehyde
, used in the manufacture of building materials (e.g., cabinetry, furniture, adhesives) may be a health problem in refugees from environmental disasters living in poorly ventilated trailers. At concentrations of 0.1 ppm or higher, it causes breathing difficulties and a burning sensation in the eyes and throat, and can trigger asthma attacks. Formaldehyde is classified as a carcinogen for humans and animals.
sick building syndrome
remains an elusive problem; it may be a consequence of exposure to one or more indoor pollutants, possibly due to poor ventilation
big 4 heavy metals
lead
mercury
Arsenic
Cadmium
Lead
competes with calcium
interferes with the normal remodeling of cartilage and primary bone trabeculae in the epiphyses in children. This causes increased bone density detected as radiodense “lead lines”; another type of lead line appears in the gums as a result of hyperpigmentation.
lead poisoning in kids vs adults
kids present with… encephalopathy, then motor neuropathies
adults present with … neuropathies
will show with basophilic stippling on peripheral blood smear
arsenic looks like
brown spots on the hands
chronic arsenic poisoning
Neurologic effects usually occur 2 to 8 weeks after exposure and consist of a sensorimotor neuropathy that causes paresthesias, numbness, and pain.
causes skin changes: hyperpigmentation and hyperkeratosis
The most serious consequence of chronic exposure is the increased risk for the development of cancers, particularly of the lungs, bladder and skin. Arsenic-induced skin tumors differ from those induced by sunlight; they are often multiple and usually appear on the palms and soles. The mechanisms of arsenic carcinogenesis in skin and lung have not been elucidated but may involve defects in nucleotide excision repair mechanisms that protect against DNA damage.
Evidence that chronic exposure to arsenic in drinking water can cause non-malignant respiratory disease
Cadmium
increased ROS and –> obstructive lung disease and kidney damage
acute alcoholism
exerts its effects mainly on the CNS, but it may induce hepatic and gastric changes that are reversible if alcohol consumption is discontinued.
hepatic change w/ alcohol
Even with moderate intake of alcohol, multiple fat droplets accumulate in the cytoplasm of hepatocytes (fatty change or hepatic steatosis). The gastric changes are acute gastritis and ulceration.
alcohol and the CNS
In the CNS, alcohol is a depressant, first affecting subcortical structures (probably the high brain stem reticular formation) that modulate cerebral cortical activity. Consequently, there is stimulation and disordered cortical, motor, and intellectual behavior. At progressively higher blood levels, cortical neurons and then lower medullary centers are depressed, including those that regulate respiration. Respiratory arrest may follow.
chronic alcoholism
affects not only the liver and stomach, but virtually all other organs and tissues as well. Chronic alcoholics suffer significant morbidity and have a shortened life span, related principally to damage to the liver, gastrointestinal tract, CNS, cardiovascular system, and pancreas.
u world stuff with alcohol
cirrhosis, hemorrhagic pancreatitis, squamous cell carcinoma in the mouth, esophageal varices, cardio myopathy…
menopausal hormone therapy
Combination estrogen-progestin increases the risk of breast cancer after a median time of 5 to 6 years. In contrast, estrogen alone in women with hysterectomy is associated with a borderline reduction in risk of breast cancer.
MHT may have a protective effect on the development of atherosclerosis and coronary disease in women younger than age 60 years, but there is no protection in women who started MHT at an older age.
MHT increases the risk of stroke and venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism. The increase in VTE is more pronounced during the first 2 years of treatment and in women who have other risk factors such as immobilization and hypercoagulable states caused by prothrombin or factor V Leiden mutations.
Oral Contraceptives (OCs)
Breast carcinoma: The prevailing opinion is that OCs do not increase breast cancer risk.
Endometrial cancer and ovarian cancers: OCs have a protective effect against these tumors.
Cervical cancer: OCs may increase risk of cervical carcinomas in women infected with human papillomavirus, although it is unclear whether the increased risk merely reflects greater sexual activity in women on OCs.
oral contraceptives and thromboembolism
Most studies indicate that OCs, including the newer low-dose (less than 50 µg of estrogen) preparations, are associated with a threefold to sixfold increased risk of venous thrombosis and pulmonary thromboembolism due to a hypercoagulable state induced by elevated hepatic synthesis of coagulation factors. This risk may be even higher with newer “third-generation” OCs that contain synthetic progestins, particularly in women who are carriers of the factor V Leiden mutation. To put this complication into context, however, the risk of thromboembolism associated with OC use is two to six times lower than the risk of thromboembolism associated with pregnancy.
oral contraceptives and cardiovascular disease
It seems that OCs do not increase the risk of coronary artery disease in women younger than 30 years or in older women who are nonsmokers, but the risk does approximately double in women older than 35 years who smoke
oral contraceptives and hepatic adenoma
There is a well-defined association between the use of OCs and this rare benign hepatic tumor, especially in older women who have used OCs for prolonged periods. The tumor appears as a large, solitary, and well-encapsulated mass.
overdose of acetaminophen
–> hepatocyt necrosis
liver failure
overdose of aspirin –>
tinnitis
also initially respiratory acidosis, then alkalosis
cocaine
Cardiovascular effects.
Tachycardia, hypertension, and peripheral vasoconstriction.
Myocardial ischemia by causing coronary artery vasoconstriction
Lethal arrhythmias
CNS. The most common acute effects on the CNS are hyperpyrexia (thought to be caused by aberrations of the dopaminergic pathways that control body temperature) and seizures.
Effects on pregnancy. In pregnant women, cocaine may cause acute decreases in blood flow to the placenta, resulting in fetal hypoxia and spontaneous abortion. Neurologic development may be impaired in the fetus of pregnant women who are chronic drug users.
cocaine and neurotransmission
inhibits reuptake of the neurotransmitters dopamine and norepinephrine –>
CNS: euphoria, paranoia, hyperthermia,
Sympathetic neuron: hypertension, cardiac arrhythmia, myocardial infarct, cerebral hemorrhage and infarct
Opiates
talc in the heroin –> granuloma in the lung
lymphangitis from needle tracks
infections
heat exhaustion
hot, sweaty, pupils dilated
normal or subnormal temp
heat stroke
dry hot skin, pupils constricted, very high body temperature
Hypothermia: direct and indirect effects
Direct effects are probably mediated by physical disruptions within cells by high salt concentrations caused by the crystallization of intra- and extracellular water.
Indirect effects result from circulatory changes, which vary depending on the rate and duration of the temperature drop. Slow chilling may induce vasoconstriction and increase vascular permeability, leading to edema and hypoxia. Such changes are typical of “trench foot.” This condition developed in soldiers who spent long periods of time in waterlogged trenches during the First World War (1914-1918), frequently causing gangrene that necessitated amputation. With sudden, persistent chilling, the vasoconstriction and increased viscosity of the blood in the local area may cause ischemic injury and degenerative changes in peripheral nerves. In this situation, vascular injury and edema become evident only after the temperature begins to return to normal. However, during the period of ischemia, hypoxic changes and infarction of the affected tissues (e.g., gangrene of toes or feet) may develop.
radiation –>
may injur cells directly or indirectly by generating free radicals from water or molecular oxygen
damages DNA; therefore, rapidly dividing cells such as germ cells, and those in the bone marrow and gastrointestinal tract are very sensitive to radiation injury
DNA damage that is not adequately repaired may result in mutations that predispose affected cells to neoplastic transformation
Ionizing radiation may cause vascular damage and sclerosis, resulting in ischemic necrosis of parenchymal cells and their replacement by fibrous tissue
Dietary insufficiency: 2 concepts
protein loss or calorie loss
marasmus means
no muscles
kwashiorkor
edematous. calories but no protein (albumin)
in cachexia
TNF triggers autophagy
vitamin A
from meat and veggies
made and stored in liver, cells of Ito
RETINOL ester important for eyes, lungs, kidneys (squamous or cuboidal epithelium)
vitamin D
sun
need liver to convert
need kidney to convert again
vitamin C deficiency
–> impaired collagen formation
need for wound healing
deficiency can cause bleeding of gums
obesity
Excess adiposity (obesity) and excess body weight are associated with increased incidence of several of the most important diseases of humans, including type 2 diabetes, dyslipidemias, cardiovascular disease, hypertension, and cancer
seems to cause metabolic syndrome
insulin resistance–> hyperinsulinemia–> IGF–> cancer
increases steroid hormones as well
also chronic inflammation (–> cancer)
