Environmental Pathology: Heat Illnesses, Toxins, and Heavy Metals

What is hyperthermia?

Prolonged exposure to elevated ambient temperatures.

What are heat cramps?

Muscle cramps due to loss of electrolytes from sweating, often occurring after vigorous exercise.

What causes heat exhaustion?

Results from hypovolemia due to increased dehydration; the cardiovascular system cannot compensate, leading to collapse.

What is heatstroke?

The most severe heat-related illness, characterized by high temperatures, high humidity, and physical exertion, leading to failure of thermoregulatory mechanisms.

What core temperature defines heatstroke?

Core temperature rises to more than 40°C.

Who is particularly at risk for heatstroke?

The elderly, people with underlying medical conditions, and those undergoing intense physical activity.

What are the negative effects of heatstroke?

Marked vasodilation, decreased circulating blood volume, hyperkalemia, tachycardia, and arrhythmias.

What is rhabdomyolysis?

The breakdown of skeletal muscle that can occur due to sustained contraction during heatstroke.

What is the role of RYR 1 in heatstroke?

RYR 1 regulates calcium release in muscle; heatstroke deranges its function, causing calcium leakage and increased muscle contraction.

What are heat-related deaths?

Deaths resulting from natural disease where exposure to high ambient temperatures is a comorbidity, often occurring during heat waves.

What are common findings during scene investigation of heat-related deaths?

Temperature of the residence, air conditioning status, window positions, and type of residence.

What are autopsy findings associated with hyperthermia?

Non-specific findings including visceral petechial hemorrhages and organ degeneration.

What is hypothermia?

Diagnosis of exclusion caused by prolonged exposure to ambient temperatures.

What factors contribute to hypothermia?

Wet clothing and alcohol use, which cause vasodilation and subsequent heat loss.

What is paradoxical undressing?

Removal or partial removal of clothing in hypothermia, which may suggest sexual assault.

What are Wischnewsky spots?

Focal hemorrhagic areas on the mucosal surface of the stomach associated with hypothermia.

What are the direct effects of hypothermia on cells?

Physical disruption within cells due to high salt concentrations from crystallization of intra and extracellular water.

What is cadmium and its health effects?

An industrial toxin that causes respiratory and gastrointestinal irritation, and chronic exposure leads to renal tubular dysfunction.

What are the health effects of chromium exposure?

Causes contact dermatitis, skin and mucous membrane ulcerations, gastrointestinal irritation, and lung carcinomas.

What is the most preventable cause of death in humans?

Smoking tobacco.

What is the most common form of tobacco delivery?

Cigarette smoking

What type of cancer is smokeless tobacco associated with?

Oral cancer

What are pack years in relation to tobacco use?

The number of cigarette packs smoked each day multiplied by the number of years smoking.

How many chemicals are found in tobacco smoke?

Approximately 7000 chemicals, many of which are carcinogens.

What direct effect does cigarette smoke have on the tracheobronchial mucosa?

It has a direct irritant effect.

Name two potent carcinogens found in cigarette smoke.

Polycyclic hydrocarbons and nitrosamines.

Which cancers are associated with cigarette smoking?

Cancers of the esophagus, pancreas, bladder, kidney, cervix, and bone marrow.

What nonmalignant conditions are associated with cigarette smoking?

Emphysema, chronic bronchitis, and obstructive pulmonary disease.

How does tobacco affect cardiovascular health?

It is strongly linked to the development of atherosclerosis and its complications, including myocardial infarction and stroke.

What is the main metabolic pathway for ethanol in the liver?

Ethanol is oxidized to acetaldehyde by alcohol dehydrogenase and the cytochrome P450 system.

What condition is associated with chronic ethanol consumption affecting the liver?

Fatty change, alcoholic hepatitis, cirrhosis, and increased risk of hepatocellular carcinoma.

What gastrointestinal effects can ethanol have?

Gastritis, gastric ulcers, and esophageal varices.

What neurological effects are associated with ethanol consumption?

Vitamin B1 deficiency, cerebral atrophy, cerebellar degeneration, and optic neuropathy.

What is fetal alcohol syndrome?

A condition resulting from ethanol exposure during pregnancy, causing microcephaly, growth retardation, and facial abnormalities.

What are common non-ethanol volatiles mentioned?

Methanol, acetone, isopropanol, and acetaldehyde.

What toxic effects are associated with methanol exposure?

Headache, nausea, CNS depression, severe metabolic acidosis, and ocular toxicity.

What is acetone commonly used in?

Paints, plastics, adhesives, and nail polish remover.

What are the symptoms of isopropanol toxicity?

Eye and respiratory tract irritation, headache, dizziness, nausea, and CNS depression.

What is the primary toxic effect of acetaldehyde?

It contributes to the toxic effects of alcohol consumption, such as hangovers.

What are the acute toxic effects of benzene exposure?

Drowsiness, dizziness, headaches, confusion, and unconsciousness.

What chronic health issues are associated with benzene exposure?

Aplastic anemia, leukemias, and lymphomas.

What is the main symptom of lead poisoning?

Abdominal pain, lethargy, vomiting, and anemia.

What is arsenic commonly associated with?

Acute gastrointestinal effects and peripheral neuropathy.

What are the symptoms of mercury poisoning?

Ataxia, hearing impairment, peripheral visual field defects, and convulsions.

What is cadmium exposure associated with?

Respiratory and gastrointestinal irritation, and chronic proximal tubular dysfunction.

What are the symptoms of acute acetaminophen overdose?

Mild nausea and vomiting, altered mental status, and potential liver damage.

What is the primary toxic metabolite produced from acetaminophen metabolism?

NAPQI (N-acetyl-p-benzoquinone imine).

What are the symptoms of salicylate (aspirin) overdose?

Vomiting, tachypnea, tinnitus, confusion, and metabolic acidosis.

What chronic effects can result from salicylate toxicity?

Headaches, dizziness, tinnitus, and potential CNS changes.

What is the main risk associated with chronic exposure to toluene?

Encephalopathy and cerebral atrophy.

What are the toxic effects of xylene exposure?

Mucosa irritation, nausea, dizziness, and CNS depression.