Effects of Electromagnetic Waves | Grade 10 Science DepEd MELC Quarter 2 Module 3

Summary

This video discusses the effects of electromagnetic waves on living organisms and the environment. It explains the difference between ionizing and non-ionizing radiation, highlighting their sources and potential health risks. The video covers ultraviolet, visible light, infrared, microwave, radio waves, and gamma rays, along with their applications and dangers. It emphasizes the importance of the ALARA principle (As Low As Reasonably Achievable) to minimize radiation exposure using time, distance, and shielding. Lastly, practical safety tips for reducing exposure to electromagnetic frequencies from everyday devices are shared.

Takeaways

• 🌞 Electromagnetic radiation surrounds us from both natural and man-made sources, categorized into ionizing and non-ionizing radiation.
• 🔋 Ionizing radiation removes electrons from atoms and can damage living tissues, while non-ionizing radiation lacks the energy to do so and is generally less harmful.
• 🛡️ The ALARA principle (As Low As Reasonably Achievable) emphasizes minimizing exposure to radiation through time, distance, and shielding.
• 🌅 Ultraviolet radiation from the sun helps in Vitamin D production but overexposure can lead to sunburn, skin cancer, and cataracts.
• 🔥 Infrared radiation, felt as heat, is abundant in the sun's energy, but excessive exposure can cause eye damage and contribute to the greenhouse effect.
• 📡 Microwave radiation excites water molecules in food to generate heat and can cause burns or cataracts with overexposure.
• 📱 Radio frequency waves from devices like cell phones and Wi-Fi can warm up body parts exposed to them, especially with prolonged use.
• 💡 Lasers, made from non-ionizing radiation, can cause severe burns and damage to body parts like the eyes if used improperly.
• ⚛️ Ionizing radiation, like gamma and x-rays, is powerful enough to penetrate materials and can be harmful, but is also used in medical treatments such as cancer therapy.
• 🧲 To reduce exposure to electromagnetic radiation, practical tips include limiting screen time, using speakerphones, and turning off devices at night.

Q & A

What are the two main types of radiation mentioned in the video?

The two main types of radiation mentioned are ionizing and non-ionizing radiation. Ionizing radiation can remove electrons from atoms and molecules, while non-ionizing radiation does not have enough energy to do so.

Where does ultraviolet radiation come from, and what are its effects on humans?

Ultraviolet radiation comes from the sun, welding, black lights, and UV lasers. While it is important for the production of vitamin D, overexposure can lead to sunburn, skin cancer, and cataracts over time.

How does infrared radiation affect the environment, and what is the greenhouse effect?

Infrared radiation is absorbed by the Earth's surface and clouds and then released as heat into the atmosphere. When trapped by water vapor, nitrogen, sulfur, and fluorocarbons, it causes the greenhouse effect, leading to climate change by increasing atmospheric temperature.

What principle should be followed to minimize radiation exposure, and what does it stand for?

The principle to minimize radiation exposure is called ALARA, which stands for 'As Low As Reasonably Achievable.' It means that even small doses of radiation should be avoided if they do not provide any direct benefit.

What protective measures can reduce radiation exposure based on the ALARA principle?

The three protective measures based on the ALARA principle are time, distance, and shielding. This means minimizing the time spent near a radiation source, maximizing the distance from it, and using appropriate shielding materials.

How do microwave ovens work, and what potential health effects can arise from overexposure to microwave radiation?

Microwave ovens work by exciting water molecules in food, causing them to vibrate and generate heat. Overexposure to microwave radiation can cause cataracts and skin burns.

What is the primary health risk of using cell phones according to the video?

The primary health risk of using cell phones is the warming of exposed body parts, such as the ear and head, due to the absorption of radiofrequency waves, which convert to heat.

Why are gamma rays considered both dangerous and useful?

Gamma rays are dangerous because they can penetrate most materials, including living tissues, and cause cellular damage, mutations, and cancer. However, they are also useful in treating cancer as they can target and destroy cancerous cells.

What materials can effectively shield against alpha, beta, and gamma radiation?

Alpha particles can be shielded with a sheet of paper or dead skin cells, beta particles can be blocked by a few inches of plastic or clothing, and gamma rays require dense materials like lead or depleted uranium for effective shielding.

What are some recommendations for reducing electromagnetic radiation exposure at home?

Recommendations include limiting screen time for children, using speakerphone or wired headsets for calls, keeping wireless routers in less-used rooms or turning them off at night, and using wired connections for the internet and devices whenever possible.

Outlines

00:00

🌐 Introduction to Electromagnetic Waves and Radiation

This paragraph introduces the video topic, focusing on the effects of electromagnetic waves on living things and the environment. It discusses the two types of radiation: ionizing, which can remove electrons from atoms and cause cellular damage, and non-ionizing, which lacks the energy to do so. The paragraph also briefly touches on the sources of these radiations and their placement within the electromagnetic spectrum.

05:01

🌞 Understanding Ultraviolet, Infrared, and Microwave Radiation

This section explores ultraviolet (UV), infrared, and microwave radiation, detailing their sources, uses, and effects on living organisms. UV radiation from the sun is important for vitamin D production but can cause sunburn and cancer with overexposure. Infrared radiation is primarily felt as heat and plays a role in climate change. Microwaves are discussed in the context of cooking and technological devices, with overexposure leading to cataracts and skin burns.

10:04

📞 Radiation from Radio Frequencies and the Role of Lasers

This paragraph covers the radiation emitted by radio frequencies (used in devices like cell phones) and the dangers of prolonged exposure. It explains how radiation can heat parts of the body, such as the head, when using a phone. Lasers, although not a form of radiation, are described for their concentrated light beams and their applications, along with their potential to cause damage, especially to the eyes.

15:05

⚛️ Ionizing Radiation and Its Applications

This section explains ionizing radiation and its forms, including alpha, beta, and gamma radiation. Alpha particles cannot penetrate skin but are harmful if ingested, while beta particles can penetrate skin but are stopped by materials like plastic. Gamma radiation, being the most penetrating, poses serious health risks but can also be used to treat cancer. The dangers of exposure to x-rays and other ionizing radiation in medical applications are discussed, emphasizing the importance of proper shielding.

20:07

🚼 Reducing Radiation Exposure and ALARA Principle

This final section provides practical advice on reducing exposure to electromagnetic radiation, especially for children using electronic devices. The ALARA principle (As Low As Reasonably Achievable) is introduced, highlighting time, distance, and shielding as key protective measures. Additional tips include limiting screen time, using wired connections, and keeping electronic devices away from the body. The section emphasizes the importance of awareness in everyday life to minimize radiation risks.

Keywords

💡Electromagnetic radiation

Electromagnetic radiation refers to energy that travels through space in the form of waves. It is a central theme in the video, as it includes a wide range of radiation types like radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. The video explains both natural and man-made sources of electromagnetic radiation and their effects on living things.

💡Ionizing radiation

Ionizing radiation is a form of electromagnetic radiation that has enough energy to remove electrons from atoms, potentially causing damage to living tissues. This type of radiation is more dangerous as it can penetrate deep into materials and cells, leading to health issues such as cancer. The video discusses the dangers of ionizing radiation from sources like X-rays and gamma rays.

💡Non-ionizing radiation

Non-ionizing radiation refers to lower-energy radiation that lacks the ability to ionize atoms or molecules. It includes types such as radio waves, microwaves, and visible light. The video explains that while most non-ionizing radiation is not harmful, overexposure, like from UV rays or infrared radiation, can still pose risks, such as sunburn or eye damage.

💡Greenhouse effect

The greenhouse effect is a process where infrared radiation is trapped by gases like water vapor and carbon dioxide in the Earth's atmosphere, leading to an increase in global temperatures. The video explains how infrared radiation, primarily from the sun, contributes to this effect, leading to climate change and shifts in weather patterns.

💡Ultraviolet (UV) radiation

Ultraviolet radiation is a type of electromagnetic radiation from the sun, divided into UVA, UVB, and UVC. The video highlights both its positive role in vitamin D production and its harmful effects, such as causing skin cancer, sunburn, and cataracts. The ozone layer blocks the most harmful UVC rays, protecting life on Earth.

💡ALARA principle

ALARA stands for 'As Low As Reasonably Achievable,' a safety principle aimed at minimizing exposure to radiation. The video emphasizes its importance in reducing radiation risks, particularly in everyday situations like using electronic devices. It involves using strategies like limiting time, increasing distance, and using shielding from radiation sources.

💡Gamma rays

Gamma rays are high-energy electromagnetic waves emitted by unstable atomic nuclei. They are the most penetrating form of radiation, capable of passing through most materials, including the human body. The video discusses both the dangers of gamma rays, such as causing cancer, and their medical applications, such as in treating cancerous cells.

💡Radiation shielding

Radiation shielding refers to methods or materials used to protect people from radiation exposure. Different types of radiation require different materials for effective shielding, such as lead for gamma rays. The video mentions shielding as one of the key protective measures to reduce radiation exposure, particularly in medical and industrial settings.

💡Microwaves

Microwaves are a type of non-ionizing electromagnetic radiation used in applications like microwave ovens, where they excite water molecules in food to generate heat. The video explains that overexposure to microwaves can cause health risks, such as skin burns or cataracts, if not properly controlled.

💡Visible light

Visible light is the portion of the electromagnetic spectrum that humans can see, consisting of colors from red to violet. The video discusses how visible light, while generally safe, can still cause eye and skin damage when there is excessive exposure. It also notes the role of visible light in enabling vision and being an essential part of daily life.

Highlights

Introduction to the effects of electromagnetic waves on living things and the environment.

Radiation exists in two forms: ionizing and non-ionizing radiation.

Non-ionizing radiation lacks energy to remove electrons from atoms or molecules and is mostly harmless.

Ionizing radiation removes electrons from atoms and molecules, potentially harmful to living tissues.

Ultraviolet radiation comes from the sun and plays a role in vitamin D production but can cause skin cancer and cataracts with overexposure.

Visible light, comprising seven colors, can damage eyes and skin when overexposed.

Infrared radiation, often felt as heat, contributes to the greenhouse effect and climate change.

Microwave radiation excites water molecules to heat food but can cause skin burns and cataracts with overexposure.

Radio waves, used in AM/FM radios and cell phones, can heat body parts due to absorption and conversion into heat.

Lasers, while beneficial in medical treatments and technology, can cause severe burns and damage to the eyes.

Gamma rays, a form of ionizing radiation, can penetrate most materials and are used in cancer treatment but can cause mutations and cancer if unshielded.

X-rays are classified as a carcinogen by the World Health Organization and should be limited to avoid potential long-term risks.

Neutron radiation can cause biological damage and is ten times more dangerous than gamma radiation in certain conditions.

Children should limit exposure to electromagnetic radiation from devices by following the ALARA principle (As Low As Reasonably Achievable).

Three key protective measures from radiation include limiting time, increasing distance, and using shielding effectively.

Transcripts

[Music]

hi

there in our previous lessons we

talked about electromagnetic waves and

its practical applications

in this video we are going to discuss

the effects of electromagnetic waves on

living things in the environment

if you still haven't watched the

previous lessons you can

pause this video and watch those first

to better understand

our lesson today so let's get started

radiation exists all around us from both

natural

and man-made sources it comes in two

forms

ionizing and non-ionizing radiation

ionizing radiation is a form of energy

that acts by removing electrons from

atoms and molecules of materials that

include

air water and living tissues

on the other hand non-ionizing radiation

is a form of low energy radiation that

does not have enough energy

to remove an electron from an atom or

molecule

most types of non-ionizing radiation

have not been

found to cause cancer

the dividing line between non-ionizing

and ionizing radiation

occurs in the ultraviolet part of the

electromagnetic spectrum

radiation in the ultraviolet band and

at lower energies is called non-ionizing

radiation

while at the higher energies to the

right of the ultraviolet band

is called ionizing radiation

ultraviolet radiation comes from the sun

welding black lights and uv lasers

the sun emits uva uvb

and uvc rays uvc

rays are absorbed by the ozone layer and

never actually reach the earth

both uva and uvb light are important for

humans in the production of vitamin d

however the effects of overexposure to

ultraviolet

rays can be negative and can be

immediate or delayed

sunburn skin cancer and cataracts

develop over time with excessive

exposure

the visible light portion of the

electromagnetic spectrum

can be seen by humans animals and

other organisms this type of light

consists of seven colors

red orange yellow

green blue indigo and violet

when all the colors are present at one

time the light is

white overexposure to visible light can

damage

both the eyes and skin

[Music]

infrared is used in thermal scanners

remote controls

and night vision goggles the human eye

can't see

most of the infrared spectrum about half

of the total energy the sun gives off

is in the form of infrared radiation

which we feel as heat in large amounts

this type of radiation can damaged eyes

and even cause blindness

infrared radiation from the sun is

normally absorbed by the earth's surface

and the clouds then release as heat into

the atmosphere

when the atmosphere has a lot of water

vapor

along with nitrogen sulfur and

fluorocarbons

the infrared radiation gets trapped and

causes the atmospheric temperature to

rise

this is called the greenhouse effect

temperature increases

cause changes in the weather patterns on

earth and

lead to climate change

a microwave oven works because

microwaves

excite the water molecules in food and

cause them to vibrate

generating heat and cooking the food

atoms and molecules can also emit and

absorb

microwave radiation overexposure to

microwave radiation

can cause cataracts and skin burns

am and fm radio broadcast wi-fi signals

cell phones and television use radio

frequency waves

exposure to electromagnetic fields in

this frequency range

can warm up exposed parts of the body

because

these absorb the radio wave and convert

these into heat

the frequency level determines the depth

of penetration into the body

for example using a cell phone causes

the ear

and or head to get warm

lasers aren't a form of non-ionizing

radiation

but they are made from it the word laser

is an acronym for

light amplification by stimulated

emission of radiation

lasers stimulate atoms and molecules and

cause them to produce light and

concentrate it

into a beam of radiation lasers can be

made from visible light

ultraviolet and infrared waves

[Music]

store checkout scanners laser pointers

and laser printers all use lasers

when not used properly lasers burn and

cause severe damage to our body

especially in the eye the narrow beam of

light

concentrates the effects on the retina

causing blind spots

ionizing radiation is a type of energy

released by atoms in the form of

electromagnetic waves or particles

ionizing radiation

takes a few forms alpha

beta and neutron particles and gamma and

x-rays

ionizing radiation has many beneficial

applications

including uses in medicine industry

agriculture and research as

the use of ionizing radiation increases

so does the potential for health hazards

if not

properly used or contained

alpha radiation occurs when an atom

undergoes

radioactive decay giving off a particle

called an alpha particle alpha particles

lack the energy to penetrate even the

outer layer of skin

so exposure to the outside of the body

is not a major concern

inside the body however they can be very

harmful

if alpha emitters are inhaled swallowed

or get into the body through a cut the

alpha particles can damage

sensitive living tissue

better radiation takes the form of

either an electron

or a positron a particle with the size

and mass of an electron

but with a positive charge being emitted

from an atom

it can be stopped by a thick piece of

plastic

or even a stack of paper it can

penetrate skin

a few centimeters posing somewhat of an

external health risk

however the main threat is still

primarily from internal emission

from ingested material

gamma radiation unlike alpha or beta

does not consist of any particles

instead it consists of a photon of

energy

being emitted from an unstable nucleus

gamma waves can be stopped by a thick or

dense enough layer of material with high

atomic number materials such as

lead or depleted uranium being the most

effective form of shielding

the extremely high energy of gamma rays

allow

them to penetrate just about anything

they can even pass through bones this

makes gamma rays

very dangerous they can destroy living

cells

produce gene mutations and cause cancer

ironically the deadly effects of gamma

rays

can be used to treat cancer in this type

of treatment

a medical device sends out focused gamma

rays that target cancerous cells

the gamma rays kill the cells and

destroy the cancer

the use of x-rays and radioactive

materials

in science medicine and industry

led to the documentation of radiation

burns

radiation exposure although helpful for

the diagnosis and treatment of disease

might also be harmful and protective

measures were taken to limit

exposure all x-rays are dangerous

because they can damage healthy living

cells of the body

this is the reason why frequent exposure

to x-rays should be avoided

[Music]

x-rays can cause mutations in our dna

and therefore might lead to cancer later

in life

for this reason x-rays are classified as

a carcinogen

by the world health organization while

x-rays are linked to a slightly

increased risk of cancer

there is an extremely low risk of

short-term side effects

however x-rays provide such a low dose

of radiation

that they are not believed to cause any

immediate health problems

[Music]

lastly neutron radiation consists of a

free neutron

usually emitted as a result of

spontaneous or induced nuclear fission

they can however be effectively stopped

if blocked by a hydrogen-rich material

such as

concrete or water

in living tissue neutrons have a

relatively high biological effectiveness

and are roughly 10 times more dangerous

at causing biological damage

compared to gamma or better radiation

of equivalent energy exposure

these neutrons can either cause cells to

change in their functionality

or to completely stop replicating

causing damage to the body

over time neutrons are particularly

damaging to soft tissues

like the cornea of the eye

people are exposed to natural radiation

sources

as well as man-made sources on a daily

basis

some basic information on protective

measures can greatly reduce

radiation exposure and risk for most

people

what can a parent do to reduce the

exposure of electromagnetic radiation

for example children playing with

electronic gadgets

like mobile phones laptops and tablets

are a common sight these days

the guiding principle of radiation

safety is

alara alara stands for

as low as reasonably achievable

this principle means that even if it is

a small dose

if receiving that dose has no direct

benefit

you should try to avoid it to do this

you can use three basic protective

measures in radiation safety

time distance and shielding

[Music]

time simply refers to the amount of time

you spend near a radiation source

minimize your time near a radiation

source

to only what it takes to get the job

done

if you are in an area where radiation

levels are elevated

complete your work as quickly as

possible and then leave the area

there is no reason to spend more time

around it than necessary

imagine spending the day at the beach if

you stay in the sun the entire day

you will likely get sunburned if you are

there for just a short period of time

you are less likely to get sunburned

the amount of time you are there makes a

difference

for toddlers limit screen time by one

hour of educational videos per day

you can reduce your exposure time by

keeping voice calls short

especially when you are not using

hands-free

text instead of calling whenever

possible

distance refers to how close you are to

a radiation

source maximize your distance from a

radiation source as much as you can

this is an easy way to protect yourself

because distance and dose

are inversely related if you increase

your distance

you decrease your dose

imagine you are sitting very close to a

fireplace

you can feel the heat and may even be

uncomfortable

if you go to the other side of the room

you would be more comfortable

as you move away the intensity of the

heat decreases

when talking on your cell phone your

safest bet

is speakerphone mode with your phone a

hand's length away

not quite as good is using a wired

headset

it still emits some radiation but better

than holding the phone to your head

a bluetooth headset is your third choice

it will deliver lower levels of

microwave radiation

than your cell phone but more than the

wired headset

turn your headset off when the phone is

not in use

[Music]

try not to keep your phone turned on

next to your body throughout the day

if you have a wireless router in your

house or apartment

keep it in a little used room and out of

the bedroom

or turn it off all together at night

strive to keep your bedroom as free of

electronic radiation

as possible in addition to routers

turn off cell phones wireless phones

and computers at night unplug electric

devices near the bed

to shield yourself from a radiation

source

you need to put something between you

and the radiation source

the most effective shielding will depend

on what kind of radiation

the source is emitting some

radionuclides emit

more than one kind of radiation

alpha particles can be shielded with

something

as thin as a sheet of paper or our outer

layer of dead skin cells

beta particles can be shielded

effectively

with a few inches of plastic or a layer

of clothing

gamma rays can be shielded effectively

by adding a few inches of lead or other

dense substance between you

and a source of radiation

you may be tempted to use one of the

many radiation shields on the market

but keep in mind that they may hamper

reception

causing your cell phone to churn out

more radiation

as what has been taught previously keep

away electronic devices

in areas where people always stay

especially in the bedroom

in addition to time distance and

shielding

let's include power and limit try to use

your

phone when you have the maximum number

of bars

indicating the best reception when

signal quality is poor your phone emits

more radiation

try not to use your cell phone in

elevators

cars trains or planes

cell phones draw more power and emit

more radiation in enclosed metal spaces

[Music]

connect to the internet with an ethernet

cord

not a wireless router whenever possible

when you are home use a wired landline

remember cordless phones connected to a

landline

can emit radiation much like cell phones

disable your device's wireless

connectivity software

including wi-fi bluetooth nfc

and the like otherwise your device will

continuously send out

electronic handshakes exposing you to

more emfs

or electromagnetic frequencies

lastly use a wired-only printer

as well as wired computer peripherals

like a mouse

and a keyboard alright

here's a quick recap electromagnetic

waves

vary in their wavelengths and

frequencies

higher frequency waves have more energy

of all electromagnetic waves gamma rays

have the shortest wavelengths and

highest frequencies

because of their very high frequencies

gamma rays have more energy than any

other electromagnetic wave

radiation exists all around us

from both natural and man-made sources

and comes into forms ionizing

and non-ionizing radiation

[Music]

non-ionizing radiation is a type of low

energy

radiation that does not have enough

energy

to remove an electron from an atom or

molecule

ionizing radiation is a form of energy

that acts by removing electrons from

atoms and molecules of materials

that include air water and living

tissues

reducing electromagnetic radiation

hazards

follow the alara principle which

includes

time distance and shielding

in addition power and limit

must be applied that's all for now

we will be discussing about images

formed by

plane and curved mirrors and lenses in

our next video

so stay tuned see you on our next video

and don't forget to keep your minds busy

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