Environmental Health Final Exam Study

Occupational Medicine

A specialized medical field that focuses on the detection and prevention of diseases that arise from the work environment. It aims to safeguard employee health against specific workplace hazards.

Occupational Disease

Defined as health outcomes that are caused or influenced by exposure to general conditions or specific hazards encountered in the work environment. The recognition of these risks dates back to mining during Greek and Roman times.

Bernardino Ramazzini (Overview)

Known as the father of occupational medicine who published his influential book Diseases of Workers in 1700. He was instrumental in describing the specific manifestations of various occupational diseases.

Bernardino Ramazzini (Advanced Contributions)

He highlighted the severe risks associated with hazardous chemicals and dusts alongside metals used in the workplace. His early work laid the historical foundation for modern workplace safety regulations.

Triangle Shirtwaist Company Fire

A historically significant occupational accident that occurred in New York City on March 25, 1911. The tragedy resulted in the deaths of 146 women within 15 minutes because doors were locked and fire escapes were nonfunctional.

Gauley Bridge Disaster

A major workplace tragedy that began around 1931 caused by exposing unprotected workers to high levels of silica dust. It resulted in approximately 1,500 cases of silicosis and 1,000 deaths.

Nonfatal Occupational Injuries and Illnesses

During 2015 a total of 1,153,490 cases of nonfatal occupational injuries were reported in private industry. Sprains and strains are consistently the leading causes of these disabling conditions.

Costs of Occupational Injuries

The financial burden of workplace accidents is massive with estimated direct costs hitting 45.8 billion dollars in 2002. Indirect costs during the same period were estimated to reach a staggering 229 billion dollars.

Agents of Occupational Disease

Workplace health threats stem from various agents including noise and toxic heavy metals along with carbon monoxide. Other major agents involve microbial exposures and repetitive motion alongside work-related stress.

Noise and Ototoxic Agents

The term ototoxic refers specifically to agents that can produce permanent hearing loss among workers. These agents include very loud sounds as well as several classes of drugs and chemicals used in the work environment.

Toxic Heavy Metals and Their Fumes

Metals such as arsenic and lead alongside mercury and cadmium pose potential severe hazards to human health. Processing and milling these materials puts workers at high risk of breathing toxic fumes and dusts.

Carbon Monoxide (CO)

An odorless and hazardous toxic gas that causes death by depriving the human body of oxygen. Workers with preexisting conditions such as lung disease and heart disease or anemia are at increased risk for its severe effects.

Microbial Agents in the Workplace

Workers in healthcare and agriculture alongside those handling sewage face significant health risks from microbial sources. These occupational categories face potential exposure to bacteria and viruses as well as disease-carrying insects.

Work-Related Stress

Chronic job stress has been implicated in a range of somatic conditions like coronary heart disease and mental disorders including depression. The term going postal specifically refers to employees who react to these stressful environments by committing violent acts.

Allergic and Irritant Dermatitis

The skin represents the most common site of contact with hazardous chemicals in the workplace. High-risk activities for this condition include manufacturing and construction alongside food production and metal plating.

Occupational Respiratory Diseases

These are often chronic conditions featuring long latency periods linked to workplace particulate exposure. Examples include asbestosis and coal workers pneumoconiosis alongside silicosis and mesothelioma.

COPD and Asthma in the Workplace

About 15 to 20 percent of COPD and asthma cases are directly linked to occupational exposures. Asthma holds the distinction of being the most frequently diagnosed occupational respiratory disease in occupational medical clinics.

Fertility and Pregnancy Abnormalities

Workplace chemical exposures can lead to severe reproductive issues like birth defects and prematurity alongside spontaneous abortions. While thousands of chemicals are used annually only about 4,000 have been formally tested for adverse reproductive effects.

Hearing Loss Caused by Noise

Prolonged exposure to loud workplace noises affects as many as 22 million workers in the United States. Beyond physical damage it can trigger psychological reactions that adversely impact the immune system and overall well-being.

Sound Pressure Level (SPL)

A critical measure of the intensity of sound within an environment. It is reported on a logarithmic scale that utilizes decibels to quantify acoustic energy.

Decibels (dBs)

A logarithmic unit used to measure sound intensity where an increase of 10 dB equates to a 10-fold increase in sound intensity. This scale is highly advantageous for characterizing the massive range of sounds that the human ear can perceive.

Permissible Noise Levels in the Workplace

The NIOSH recommended exposure limit or REL is set at 85 dBA for a standard 8-hour shift. The dBA designation refers to A-weighting which means the exposure is calculated as an 8-hour time-weighted average.

Musculoskeletal Disorder (MSD)

Defined as an injury or disorder affecting the muscles and nerves alongside tendons and joints or spinal disks. These injuries frequently stem from repetitive motion and heavy lifting in various occupational settings.

Traumatic Injuries and Fatalities

The Bureau of Labor Statistics reported a total of 4,836 fatal occupational injuries in the year 2015. The industries suffering the largest numbers of deaths include construction and transportation alongside agriculture and forestry.

Job Stress

Defined as the harmful physical and emotional responses that occur when job requirements do not match worker capabilities or resources. Conditions associated with this phenomenon include anxiety and neurotic disorders alongside critical incident stress.

Preventing Occupational Disease (Primary Methods)

The primary methods for protecting workers include engineering controls like quieter machinery and improved building ventilation. Other preferred primary methods include the modification of work practices and administrative controls like work shift rotation.

Personal Protective Equipment (PPE)

Apparatuses designed to protect employees from serious workplace injuries resulting from contact with chemical or radiological hazards. Examples include respirators for airborne hazards and ear muffs for hearing protection alongside safety goggles.

Public Health Surveillance

Involves surveillance systems that collect comprehensive information about occupational injuries and illnesses. These systems maintain essential databases on exposures to occupational hazards to guide safety regulations.

US Agencies That Conduct Surveillance

Federal oversight of occupational health is managed by several key organizations including NIOSH and OSHA. Other involved agencies include the National Center for Health Statistics and the Mine Safety and Health Administration.

Threshold Limit Value (TLV)

Refers to airborne concentrations of substances and represents conditions under which it is believed nearly all workers may be unaffected. These serve as critical guidelines and regulations for the limitation of workplace exposures.

Foodborne Diseases and Infections

These are illnesses acquired strictly by the consumption of contaminated food or beverages. While often commonly referred to as food poisoning this colloquial term is technically inaccurate.

Foodborne Outbreak

Defined as the occurrence of a similar illness among two or more people which an investigation linked to the consumption of a common meal. An exception is botulism where even a single case officially constitutes an outbreak.

Global Burden of Foodborne Illness

These illnesses act as a major cause of morbidity and occasional mortality worldwide including industrialized nations. Contributing factors to their global increase include changes in agricultural methods and the globalization of food distribution.

Foodborne Illness in the US

Contaminated food affects almost one-quarter of the population each year in the United States. This massive health burden causes an estimated 9,000 deaths and incurs an economic cost of 5 billion dollars annually.

FoodNet

The Foodborne Diseases Active Surveillance Network is operated by the CDC at the federal level. It utilizes an active system where public health officials maintain direct contact with laboratory directors to rapidly identify new cases.

Four Major Categories of Food Hazards

Food can be compromised by biological agents like bacteria and physical hazards like glass or metal. The other two main categories are chemical contaminants and nutritional hazards involving excessive or deficient nutrients.

Salmonella

Rod-shaped motile and gram-negative bacteria that do not form spores. The most common serotypes in the United States include Enteritidis and Typhimurium which cause severe gastrointestinal illness.

Salmonellosis

An infection ranked among the most frequent types of foodborne illness with approximately one million cases estimated annually in the US. Common sources include wild and domestic animal reservoirs such as poultry and swine and even pet turtles.

Clostridium botulinum

An anaerobic bacteria that grows in oxygen-free environments and produces a potent neurotoxin. It causes a severe form of foodborne intoxication called botulism which directly affects the human nervous system.

Effects of Botulism

Early signs include marked lassitude and vertigo alongside double vision and progressive difficulty speaking and swallowing. Symptoms typically onset between 18 and 36 hours after ingestion but can vary from 4 hours to 8 days.

Clostridium perfringens

An anaerobic rod-shaped bacteria that forms spores and causes roughly one million cases of foodborne illness yearly in the US. It occurs commonly in soils and sediments especially in areas heavily contaminated with feces.

Escherichia coli O157:H7

While many strains reside harmlessly in the intestines this specific pathogenic strain causes hemorrhagic colitis linked to bloody diarrhea. Major outbreaks have been traced to hamburger chains leading to 73,000 cases and 61 deaths yearly in the US.

Staphylococcus aureus

A bacteria residing in the nose and throat and skin lesions of humans and animals. It elaborates a toxin that is highly resistant to high temperatures and causes rapid-onset foodborne intoxication often linked to ham.

Trichinosis

A disease associated with eating meat that contains a nematode roundworm from the genus Trichinella. The classic agent is Trichinella spiralis which is found in carnivorous and omnivorous animals like pigs and bears.

Tapeworms (Taeniasis)

A parasitic disease caused by consuming raw or undercooked infected beef or pork containing tapeworms. Symptoms include mild abdominal distress and the passage of proglottid sections containing eggs in human stools.

Hepatitis A in Food

A viral agent that causes approximately 1,600 foodborne cases annually in the United States. It is commonly transmitted through shellfish and salads contaminated by infected workers in food processing plants and restaurants.

Norovirus

A highly contagious virus transmitted easily within closed environments such as cruise ships where crew members may act as disease reservoirs. Symptoms include vomiting and diarrhea alongside dehydration typically lasting for one to two days.

Prions (Bovine Spongiform Encephalopathy)

Infectious agents causing BSE which is a progressive and ultimately fatal neurological disease in cattle. The disease appears to spread among livestock through agricultural feeds that contain rendered cattle products.

Variant Creutzfeldt-Jakob Disease (vCJD)

The human form of the neurological disease that has been linked causally to bovine spongiform encephalopathy. Human cases are thought to occur specifically due to dietary exposure to BSE-contaminated beef agents.

Marine Toxins

Naturally occurring chemical toxins found in seafood that can trigger severe foodborne illness. Specific examples include ciguatoxin and scombroid toxin alongside paralytic shellfish poison and puffer fish toxin.

Heavy Metals in Food

Toxic metals can leach into acidic foods from containers or contaminate poultry when arsenic is used to control chicken parasites. High concentrations of these metals can cause violent vomiting within a few minutes to an hour after ingestion.

Pesticides in Foods

Applied to crops to reduce insect damage but often leave persistent chemical residues on food products. Dietary consumption is one of the principal means of human exposure to persistent organic chemicals like organochlorines.

Antimicrobials in Meat

Antibiotics like amoxicillin and penicillin are routinely employed for disease prevention and growth enhancement among agricultural livestock. This practice creates hazardous residues in meat and accelerates the dangerous evolution of antibiotic-resistant microorganisms.

Food Additives

Chemicals intentionally added to foods to improve quality or incidentally introduced during packaging and storage. They also include malicious additives such as poisons that saboteurs intentionally introduce into food supplies.

Intentional Preservatives

Additives like sodium nitrate and sulfites used specifically to arrest the proliferation of dangerous microbes. Antioxidants like BHA and BHT are also used to prevent fatty foods from acquiring a rancid taste or turning brown.

Delaney Clause

A crucial part of the 1958 Food Additives Amendment that established strict early safety baselines. It outright prohibited the use of any additives or pesticides that had been determined to cause cancer in humans or animals.

Food Quality Protection Act (1996)

A major regulatory update that officially repealed the strict zero-tolerance Delaney Clause. It established a new standardized threshold that a substance could not cause a lifetime incidence of more than one cancer case per one million exposed persons.

Safe Holding Temperatures

Proper thermal control is essential to prevent foodborne illness by keeping hot foods above 140 degrees Fahrenheit and cold storage below 40 degrees Fahrenheit. The dangerous temperature range for microbial growth lies precisely between 40 and 140 degrees Fahrenheit.

Irradiation of Foods

A safety procedure where energy from ionizing radiation is passed through foods to destroy bacteria and pathogens. Often referred to as cold pasteurization it is certified as a safe method that does not cause the food to become radioactive.

Hazard Analysis of Critical Control Points (Overview)

A systematic approach begun in the 1950s designed explicitly for reducing the risk of foodborne illness. Under HACCP foods are rigorously monitored at critical points from the time of harvest to the time of consumption.

Hazard Analysis of Critical Control Points (Seven Principles)

The comprehensive framework begins with performing a hazard analysis and deciding on critical control points. It requires establishing critical limits and monitoring procedures alongside corrective actions and comprehensive record keeping.

Smog

A dangerous mixture of pollutants principally featuring ground-level ozone produced by complex chemical reactions in the air. These reactions typically involve smog-forming chemicals emitted by both anthropogenic and natural sources.

Health Effects of Air Pollution

Exposure leads to impairment of lung and breathing function and damage to vital organs like the nervous system. It is also directly linked to certain forms of cancer including lung cancer and skin cancer resulting from ozone layer depletion.

Notorious Air Pollution Episodes

Major historical events highlighting the lethal nature of atmospheric pollution occurred in the Meuse Valley of Belgium in 1930. Other highly fatal smog episodes took place in Donora Pennsylvania in 1948 and London England in 1952.

Composition of Pure Air

By weight pure atmospheric air is composed predominantly of Nitrogen at 76 percent and Oxygen at 23 percent. Argon makes up 1 percent while Carbon dioxide represents a mere 0.03 percent of the mixture alongside water vapor.

Natural Sources of Air Pollution

Non-human atmospheric contaminants include wind storms that spread massive dust clouds and salt evaporation along global coasts. Other massive natural inputs include forest fires and volcanic eruptions alongside biological materials like mold spores and pollen.

Stationary Sources of Air Pollution

Massive immobile anthropogenic contributors to atmospheric degradation like electric generating plants and oil refineries. This category also encompasses large factories and chemical plants alongside municipal waste incinerators.

Mobile Sources of Air Pollution

Moving anthropogenic contributors including on-road vehicles like cars and trucks alongside nonroad vehicles like airplanes and ships. The EPA states that motor vehicles produce approximately half of two major smog causes namely VOCs and nitrogen oxides.

Criteria Air Pollutants

A designated group of very common air pollutants regulated heavily by the EPA based on health and environmental criteria. The core list includes ozone and nitrogen oxides alongside carbon monoxide and sulfur dioxide and particulate matter and lead.

Particulate Matter (PM)

Airborne particles categorized by size into PM10 and PM2.5 that cause severe respiratory irritation and bronchitis. The extremely fine PM2.5 particles are inhaled deeply into the lungs and are associated with 60,000 deaths annually in the US.

Acid Rain (Overview)

The precipitation of acidic compounds formed when sulfur dioxide and nitrogen oxides interact with atmospheric water and oxygen. These foundational emissions are heavily produced by industrial installations such as coal-fired electric utility plants.

Acid Rain (Environmental Impact)

The transformed acid particles travel long distances before falling as rain or snow to create abnormally high environmental acidity. This chemical alteration is potentially devastating to forest soils and aquatic stream ecosystems alongside human health.

Temperature Inversion

An atmospheric condition during which a warm layer of air stalls aggressively above a layer of cool air closer to the surface. This weather phenomenon prevents upward mixing and causes dangerous pollutants to build up and trap close to the earth.

Diesel Exhaust

A complex and hazardous mixture of condensed hydrocarbon gases and solid carbon particles. It contains hundreds of organic and inorganic toxic compounds including polycyclic aromatic hydrocarbons which are suspected carcinogens.

Health Effects of Diesel Exhaust

Epidemiologic studies comparing heavily exposed workers like truck drivers and railroad crews demonstrate severe respiratory risks. Individuals exposed directly have lung cancer incidence rates that are 20 to 40 percent higher than unexposed groups.

Air Quality Index

A public health tool used to provide citizens with a simplified indication of local atmospheric conditions. It focuses specifically on the acute health effects one may experience within a few hours or days after breathing polluted air.

National Ambient Air Quality Standards (NAAQS)

Federal standards for air pollution determined by the EPA based on current comprehensive literature reviews. Primary standards provide public health protection while secondary standards provide public welfare protection against visibility and crop damage.

Acute Effects of Air Pollution

Short term immediate reactions to poor air quality including aching lungs and irritation of the eyes nose and throat. These exposures routinely trigger immediate bronchitis and pneumonia alongside wheezing and headaches.

Chronic Effects of Air Pollution

Long term deterioration of health resulting in devastating conditions like heart disease and chronic obstructive pulmonary disease. Sustained exposure is also a major globally recognized contributor to the development of lung cancer.

Poor Indoor Air Quality

A massive health concern since many people spend up to 90 percent of their time indoors. Poor indoor air heavily exacerbates asthma and is closely associated with conditions like Legionnaires disease and multiple chemical sensitivity.

Indoor Air Pollution Sources

Indoor contaminants stem from mold and bacteria alongside carbon monoxide fumes from attached garages. Other pervasive sources include chemicals released from building materials and tobacco smoke and radon gas seeping through foundations.

Sick Building Syndrome vs Building-related Illness

Sick building syndrome causes acute comfort effects where no specific illness or cause can be identified. In contrast building-related illness is a highly specific diagnosable medical condition directly linked to identifiable building pollutants.

Global Warming

An increase in the near surface temperature of the Earth predicted to occur due to increased emissions of greenhouse gases. Scientists generally agree that the Earth's surface has already warmed by about 1 degree Fahrenheit in the past 140 years.

Causes of Global Warming

The primary driver is the massive combustion of fossil fuels like coal and petroleum-based fuels. Additionally chlorofluorocarbon gases historically used in air conditioners contribute directly while also depleting the protective ozone layer.

Potential Impacts of Global Warming

Climatic shifts will cause profound disturbances in native plant habitats and fuel the geographic expansion of vector-borne diseases. Extreme climatic conditions like massive droughts and heat waves will severely disrupt the global food supply.

Air Pollution in the United States

Despite having only about 4 percent of the world population the US produces 23 percent of greenhouse gas emissions. The nation stands as the second leading source of global carbon dioxide primarily due to coal-fired plants and combustion engines.

Technological Controls for Emissions

Industrial engineering solutions designed to capture pollutants before they enter the atmosphere. These essential mechanical devices include scrubbers and filters alongside high-efficiency electrostatic precipitators.

The Kyoto Protocol

An international legally binding compact initiated in Japan in 1997 aimed at reducing greenhouse gas emissions. It required developed countries to reduce emissions by targeted amounts but the United States famously did not ratify it.

Paris Agreement

A legally binding climate agreement adopted by 195 countries in December 2015. It aggressively sought to limit global temperature rise to 2 degrees Celsius although the United States announced withdrawal in June 2017.

Waste vs Hazardous Waste

Waste generally refers to materials perceived to be of negative value intended for disposal. Hazardous waste represents a highly specific subset of materials that are potentially dangerous to human health or the environment.

Pollution

The introduction into the natural environment by humans of substances or materials or energy that cause environmental hazards. The growing volume of municipal waste has led to massive increases in pollution across aquatic environments and oceans.

Municipal Solid Waste (MSW)

Everyday trash or garbage produced by residents and businesses alongside public institutions. In 2008 the United States generated approximately 258 million tons of MSW before accounting for recycling efforts.

The Four Dimensions of MSW Disposal

The comprehensive management of trash relies on four distinct physical disposal pathways. These pathways include recycling and landfilling alongside large-scale composting and combustion for energy recovery.

EPA Hierarchy for Management of MSW

The federal government ranks waste management strategies from most environmentally favored to least favored. Source reduction and reuse are the most preferred followed by recycling and energy recovery with raw disposal acting as a last resort.

Source Reduction

The most environmentally preferred strategy defined simply as reducing waste precisely at the source of production. Its main components include waste reduction to generate less material and waste recycling to reuse materials in the stream.

Recycling

The formal process of collecting and reprocessing a resource so it can be utilized again in manufacturing. Common everyday items processed through this system include aluminum cans and paper alongside glass bottles.

Advantages of Recycling

Reprocessing materials drastically reduces greenhouse gas emissions and decreases the massive volume of materials shipped to landfills. It preserves essential natural resources while opening up new manufacturing employment opportunities and saving energy.

Composting

The aerobic biological decomposition of organic materials like leaves and food scraps to produce a stable humus-like product. This natural biodegradation process produces a useful material that resembles soil and is excellent for gardening.

Landfill Design

A modern sanitary landfill is carefully constructed of four major protective components. It requires a dense bottom liner and a system for collecting leachates along with a cover and an appropriate isolated location.

How a Landfill Works (Containment)

The bottom is lined securely with dense clay and thick plastic sheeting to completely contain hazardous leaks. A flexible membrane holds in toxic chemicals while a dedicated leachate sump collects fluids for further advanced treatment.