Environmental Conditions

Types of Environmental Health Issues

• Hyperthermia• Hypothermia• Altitude• Sunburn• Lightning• Air Pollution

Heat

• Heat illness is a serious threat to health, but it is preventable

Physiology

• Metabolic Heat Production– Normal metabolic function results in heat

production (“burning” of calories)

• Therefore, we need to find a way to dissipate the heat in order to maintain normal body temperature

Heat Exchange

• Conduction – direct contact (loss or gain)• Convection – circulation (loss or gain)• Radiation – sun (heat gain only)• Evaporation (heat loss only)– When radiant heat and environmental

temperature is greater than body temperature, the body must cool via sweat evaporation• Cannot evaporate sweat in relative humidity of 75% or

more

Heat Index

• Wet Bulb Globe Temperature Index (WBGT)– Incorporates

• Dry bulb – standard air temperature

• Wet bulb – heat with humidity• Black bulb – radiant heat

– These readings together provide a heat index reading that yields exercise recommendations

– WBT and DBT are measured using a sling psychrometer (manual or digital)

Heat Index

Heat Index

The sun’s heat is an example of this type of heat exchange:

1 2 3 4 5

20% 20% 20%20%20%1. Conduction2. Convection3. Radiation4. Evaporation5. None of the above

Heat Illness

• Heat Rash (prickly heat)– Red, raised rash that stings from sweat

• Heat Syncope (fainting)– Associated with rapid fatigue, overexposure to

heat, and long periods of standing

• Heat Cramps– Due to dehydration and electrolyte imbalance

Heat Illness• Heat Exhaustion

– Result of dehydration and overexertion– Cardiac output drops– S&S

• Profuse sweating• Pale skin• Mild elevation in temperature• Dizziness• Nausea• Vomiting/diarrhea• Hyperventilation• Muscle cramps• Loss of coordination

– Must be hydrated and cleared by a physician to return to play

Heat Illness• Heat Stroke– Life – threatening condition– Sudden onset

• Collapse• Loss of consciousness• Dysfunction of the central nervous system• Flushed, hot, dry skin (minimal sweating)• Shallow breathing• Strong rapid pulse• High core body temperature

– Drastic cooling measures must be implemented– Constant core temperature evaluation– Remove from cold tub when core temp reaches 10

Prevention of Heat Illness• Stay cool and ingest fluids• Drink before thirsty

– 1-2% drop in body weight indicated dehydration• Modify exercise in hot humid climates• Allow athletes unlimited access to water• Sports drinks

– Replaces electrolytes– Flavor enhances desire to drink

• Aclimitization– Preseason conditioning – graded conditioning over 7-10 days– 80% acclimitization can occur in the first 5-6 days of double

practices

Prevention of Heat Illness• Identify those who are at risk– Athletes with large muscle mass– Overweight athletes– Women are physiologically more efficient with

temperature regulation– Individuals with

• Poor fitness• History of heat illness• Heart conditions

• Wear light clothing that is breathable• Weight records• Temperature and humidity readings

Heat exhaustion is a medical emergency and is the most severe

heat illness.

1 2

50%50%1. True2. False

Hypothermia is a heat related illness.

1 2

50%50%1. True2. False

Hypothermia

• Most activities in sport allow for adequate heat production (watch warm up and down times)

• Temperature in combination with wind chill, and wetness increases chance of hypothermia

Prevention of hypothermia

• Wear gear that wicks moisture away from skin• Windproof and waterproof fabrics• Dress in layers• Hydration assists with heat maintenance• Associated cold injuries– Frost nip, frost bite– Raynaud’s Syndrome

Altitude• Natives– Larger chest capacity, more alveoli, capllaries, and red

blood cells• Residents– Partial adaptations include

• Increased mitochondria, hemoglobin and glycogen conservation

• Visitor– Increased breathing and heart rates– Changes in blood flow and enzyme activity– Takes 2-3 weeks to adjust

Altitude illness• Acute mountain sickness

– Due to disruption in fluid balances in the brain– Headache, nausea, vomiting, sleep disturbance, dyspnea

• Pulmonary edema– Lungs accumulate fluid– Dyspnea, cough, headache, weakness, LOC

• Sickle Cell Trait– 8-10% of African Americans have this trait

• High red blood cell hemoglobin– In high altitudes, the blood is deoxygenated, and the RBC’s

clump together, causing deoxigenation of the tissues and tissue death.

– Results in enlarges spleen and possibly rupture

Lightning

Lightning is only seen after it has hit the ground, and is travelling back to the sky

Lightning Safety

• #2 Cause of death by weather phenomena• For safety of athletes and spectators, there

must be a plan of action• Safety– Avoid large trees, flag/light poles, standing water,

telephones, bleachers, pools, showers, umbrellas, other metal objects

– If hair stands up on your hand, you are in imminent danger and should minimize the surface area for the lightning to strike

Lightning Safety

• Flash to bang method– Estimates the distance of the storm from your

location• Count the time from the flash of lightning to the sound

of the thunder– 5 seconds = 1 mile– 30 seconds indicated inherent danger– 15 seconds - should evacuate the field– May return to the field 30 minutes following the last sound of

thunder

If the hair on your head stands up, you should lie flat on the ground so

the lightning doesn’t strike you.

1 2

50%50%1. True2. False

Air Pollution• Problem in urban areas• Types

– Photochemical haze – nitrogen dioxide and stagnant air• When mixed with sun, creates and ozone

– Smog – carbon monoxide (effects lungs and cognitive performance)and sulfur dioxide (effects lung capacity and efficiency)

• Ozone– Athletes may experience shortness of breath, coughing, chest

tightness, pain with deep breathing, nausea, eye irritation, fatigue, lung irritation, etc

– Asthmatics are at greater risk of symptoms– May become desensitized over time