Ch10: Environmental Pathology Flashcards
What are three major determinants of our health?
- Air we breath
- Food and water we consume
- Exposure to toxic agents
What is an environmental disease?
Condition caused by exposure to chemical or physical agents in a person’s environment
What is overall fatality rate of occupational injuries?
4.8 per 100,000 workers
Who set the standard for reporting health information?
Global Burden of Disease
What is the GBD statistic for assessing premature mortality and disease morbidity?
DALY (Disability adjusted life year)
What is the DALY statistic?
adds the years of life lost to premature mortality with the years lived with illness and disability.
What is said to increase due to human activity in regards to climate change?
- CO2
- Methane
- Ozone
Causes of increased CO2? (2)
- Combustion of hydrocarbons in automobiles and energy plants
- Deforestation
Problems with human health in regard to climate change? (4)
- CV, Cerebrovascular, Respiratory disease
- Gastroenteritis and infectious disease
- Vector-borne infectious diseases
- Malnutrition
What is the definition of poison?
A dose that causes harmful effects instead of helpful
How many pounds of carinogenic toxic chemicals are released per year in the US?
4 billion pounds
What 4 agencies determine exposure limits?
EPA
FDA
OSHA
CPSC
The EPA regulates what?
Exposure to peticides, toxic chemicals, water and air pollutants
The FDA regulates what?
drugs, medical devices, food additives, and
cosmetics
What does OSHA mandate?
employers provide safe working conditions for
employees
What does CPSC regulate?
other products sold for use in homes, schools, or
recreation
What are xenobiotics?
Exogenous chemicals in the air, water, food
and soil that may be absorbed into the body
through inhalation, ingestion, and skin contact
Where do xenobiotics act? (2)
Site of entry
Transported to distant tissues by BV’s
What xenobiotics are metabolized to form inactive water-soluble products or activated to form toxic metabolites? 2
Solvents
Lipophilic drugs
Most important catalyst of phase I reactions is what?
Cytochrome p450 system
Carbon tetrachloride is metabolized to what in the liver?
Toxic trichloromethyl free radical
Benzo-alpha-prene is metabolized to what?
DNA-binding metabolite carcinogen
Xenobiotics are typically eliminated how?
Phase I reaction
Phase II reaction to soluble metabolite
Eliminated from body
What does Radon cause?
Lung disease and cancer
EPA has limits for what 6 pollutants?
- Ozone
- Nitrogen oxides
- Sulfur dioxide
- Particulates
- CO
- Lead
Smog is what?
Smoke and fog
What leads to formation of ozone layer?
Interaction of UV radiation and oxygen in the stratosphere
Why is the ozone layer good?
Absorbs the most dangerous UV from sun
What causes ozone layer loss?
Halocarbons like CFP’s
Toxicity of ozone is due to what?
Production of free radicals that injury lung epithelial cells and Type I alveolar cells
How does ozone cause release of inflammatory mediators?
Oxidizes lipids to H2O2 which acts as irritant
Overall effect of ozone on lungs? (3)
- Increase epithelial permeability
- Increased reactivity of airways
- Decreased ciliary clearance
Nitrogen dioxide does what in the airway?
Dissolves in water to form nitric acid which damages airway epithelium
Sulfur dioxide is produced by who? 2
Power plants burning coal and oil
Byproduct of mills
SO2 is absorbed in airways where it releases what? (3)
Effect of this?
H+, HSO- (bisulfite), SO3 (sulfite)
Local irritation
Particulate matter like soot is most hazardous at what size?
Ultrafine (<10 um)
What is effect of ultrafine soot in lungs?
Phagocytosed by macrophages which causes release of inflammatory mediators that damage lungs
What is anthracosis?
Black pigment in lungs
3 main effects of soot in lungs?
- Cytokine release systemically
- Increased blood viscosity
- Autonomic changes affecting the heart
Carbon monoxide has what four characteristics?
- nonirritating
- colorless
- tasteless
- Odorless
What produces CO?
Incomplete oxidation of carbon materials
Greatest danger of CO toxicity is when?
Working in confined environments with high exposure (in a garage will kill in 5 minutes)
Carbon monoxide effects? 2
- CNS depressant
2. Binds to hemoglobin causing loss of oxygen
Severe hypoxia occurs when with CO?
20-30% saturation
Death and loss of consciousness occur when with CO?
60-70 percent saturation
Indoor air pollution includes? (4)
- tobacco smoke
- CO
- NO2
- Wood smoke (NO’s, soot, hydrocarbons)
Formaldehyde is found in what especially?
New carpet
Radon is a decay product of what?
Uranium and is found in soil
Asbestos fibers are found where?
Houses built before 1970
Bioareosols are used for what?
Aerosolization of bacteria
What is the famous bioaerosol exposure?
Legionella pneumophilia
Lead exposure occurs through what? 3
Air, food and water
Most absorbed lead goes where?
What does it compete with?
How is it seen radiographically?
Bone and teeth
Calcium
Lead lines along growth plates
Is acute poisoning of lead common?
No.
Acute Lead poisoning is seen with what main symptoms? 2
Neurologic symptoms
GI symptoms
Why are children affected more than adults by lead?
- Absorb 50% of ingested lead compared to adults’ 15%
2. More permeable blood brain barrier
Which nervous system is affected more in children?
More in adults?
Children = CNS Adults = PNS
How does lead present in terms of blood?
Microcytic anemia with coarse basophilic stippling
When will you see the microcytic anemia with coarse basophilic stippling in lead toxic patients?
At 40 ug/ml
Arsenic intereferes with what?
Cellular longevity by interfering with oxidative phosphorylation
Signs and symptoms of acute arsenic poisoning?
- HA
- Confusion
- Convulsion
- Diarrhea
- Vomiting
- Neuropathies
Long term exposure to arsenic leads to what?
Night blindness due to Vitamin A deficiency
3 cancers caused by long term arsenic exposure?
- Cutaneous basal cells
- Squamous cell
- Lung carcinomas
Cadmium is generated where? 2
Mining
Cadmium nickel batteries
Toxicities of cadmium include what? 4
- Obstructive Lung disease
- End stage renal disease
- Skeletal problems
- Lung carcinomas
Three main forms of mercurcy?
- Elemental
- Inorganic: Mercury chloride
- Organic: Methyl mercury
Modern sources of mercury? (4)
- Contaminated sea food
- Dental
- Gold mining
- industry
Clinical manifestation of mercury? 4
- Nervous system: CNS malfunction and peripheral neuropathies
- Kidney injury
- Tremors/bizarre behavior
- Gingitivitis
What is methyl mercury particularly toxic to?
Developing CNS
Chronic exposure of mining and industrial chromium and nickel has what effect?
Increased nasal and lung carcinomas
Cause of heart disease? (4)
- CO
- Lead
- Solvents
- Cadmium
Cause of nasal cancer? 2
- Isopropyl alcohol
2. Wood dust
Cause of lung cancer? 7
- Radon
- Asbestos
- Nickel
- Arsenic
- Chromium
- Mustard gas
- Uranium
Cause of COPD? 2
- Dust
2. Cadmium
Cause of respiratory irritation? 3
- ammonia
- sulfur oxide
- formaldehyde
Cause of fibrosis in respiratory?
- Asbestos
Organic solvents are readily obsorbed where? 2
Skin
Lungs
GI
Organic solvent acute exposure can lead to what?
CNS depression/Coma
Huffing involves inhalation of what?
Organic solvents
Benzene is metabolized by what?
What do its metabolites cause? (3)
Cytochrome p450
- Bone marrow toxicity
- Leukemia
- Aplastic anemia
Polycyclic aromatic hydrocarbons are composed of what?
Aromatic rings in a flat plane
PAH’s are found in what? 4
Foundries
Tars
Soot
Tobacco smoke
What are PAH’s considered?
Most potent chemical carcinogens
PAH’s are so potent why?
Very common and highly carcinogenic
Industrial exposure to PAH’s is linked to what? 2
- Bladder carcinoma
2. Lung carcinoma
Organochlorines are lipophilic products that can resist what?
Degradation
Organochlorines have what type of activity?
Anti-estrogenic and Anti-Androgenic leading to decreased fertility rates
What are most organochlorines used for?
Pesticides
Non-pesticide organochlorines are known to cause what? 4
- Chloracne
- CNS probs
- Hepatic probs
- Induce cytochromes
What is chloracne?
Hyperpigmentation and hyperkeratosis of face and ear
Vinyl chloride is used to produce what?
Polymer polyvinyl chloride (PVC)
What will vinylchloride cause?
Anglosarcoma of liver
Mineral dust inhalation causes what?
4 Examples?
Chronic, non-neoplastic lung disease “Pneumoconioses”
- Black lung
- Silicosis
- Asbestosis
- Berylliosis
What is the most preventable cause of human death?
Smoking tobacco
How many people die due to tobacco smoke in US a year?
440,000
What are the causes of death in smokers? (10)
- Lung cancer
- Esophageal cancer
- Bladder cancer
- Oral cavity/URT cancer
- Pancreatic cancer
- Athersclerosis
- CAD
- Emphysema
- COPD
- Respiratory infections
What is the number 1 cancer killer of men and women?
Lung cancer
What % of lung cancers is tobacco responsible for?
90%
Where does lung cancer rate in terms of cancer incidence in men and women?
2
What are two ways to reduce your cigarette cancer risk?
- Delay onset of smoking habits
2. Quitting