Shadowing-Übung: Should fluoride be in our water? - Englisch Sprechen Lernen mit Video
Lektion wird erstellt...
1
This is the New York City tap water that I drink.
2
And for every liter of it, there is 0 .8 milligrams of fluoride in it.
3
Fluoride is essential for our oral health.
4
It protects us from cavities, which is why it's also in lots of toothpaste and mouthwash and in treatments we get at the dentist.
5
And for about 63 % of Americans, it's also why it's in our drinking water.
6
Now someone with a lot of views on public health not
7
supported by science is being considered to lead one of the country's top public health agencies.
8
And one thing he believes is that we should advise all U .S water systems to remove fluoride from public water.
9
Putting fluoride in the water has long fueled conspiracy theories.
10
But it turns out the science is still evolving.
11
And some of it emerged even as we made this video.
12
And it's causing some scientists to take another look at this practice and wonder: Do we still need fluoride in our water?
13
And if so, how much is safe?
14
Fluoride protects us from cavities by remineralizing enamel on our teeth.
15
It acts as a protective barrier against the acid that bacteria in our mouths produce.
16
When we drink fluoride in water, about half of it sticks around in our bodies.
17
Some of it binds to our bones, and some reaches our teeth through our saliva.
18
Fluoride occurs naturally in soil and air, and some regions have naturally occurring fluoride levels in their water.
19
Almost 100 years ago, dentists figured out that high naturally occurring levels of fluoride in the water was staining children's teeth.
20
But it was also preventing tooth decay.
21
In 1945, Grand Rapids, Michigan and Newburgh, New York were among the first communities to start fluoridating water artificially.
22
and observed that the rate of tooth decay declined by more than 60%.
23
So other communities started adopting the practice too.
24
And eventually it got added to toothpaste which works topically.
25
The goal of adding it to water was to make sure that everyone had access to fluoride's protection, regardless of whether they used fluoridated products or had access to dental care.
26
One way to figure out how well the fluoride in our
27
water is still working is to look at what happens in communities who have stopped adding it.
28
Supporters of water fluoridation point to studies like this one that looked at what happened in Calgary, Canada after they stopped fluoridating their water in 2011.
29
The rate of tooth decay in children's baby teeth was already on the rise, but after they took the fluoride out of the water, that rate spiked.
30
that added fluoride to their water, and could only determine that it may have led to a slight reduction in tooth decay.
31
The study authors found that prior to 1975, there was a clear and important effect on prevention of tooth decay in children due to water fluoridation.
32
But because of the increased availability of fluoride in toothpaste since then, it is unlikely that we will see this effect in all populations today.
33
So fluoride in the water did help us have healthier teeth in the past.
34
And it still might in some communities.
35
But because of how widespread topical fluoride is, the effect might not be as dramatic as it was historically.
36
And in recent years, a handful of scientists have been looking into another question: how much fluoride is safe?
37
Fluoride as an additive to water is usually in the form of liquid fluorosilicic acid,
38
and the World Health Organization recommends a dosage no higher than 1 .5 milligrams per liter of water.
39
you To put that in perspective, that's about one gallon for an Olympic swimming pool amount of water.
40
The CDC recommends 0 .7 milligrams per liter of water, or a little less than a half gallon per swimming pool.
41
Municipalities set their own fluoride doses, and most set it around this amount, like my New York City tap water.
42
This CDC recommendation is solely based on an amount
43
that balances the protection from tooth decay while limiting the risk of dental fluorosis, the mostly harmless tea staining first observed in communities with high natural fluoridation.
44
But scientists studying these dosages today are looking at how fluoride affects developing brains, both in utero and as young children, primarily by measuring IQ.
45
What we've learned about the developing brain is it's probably one of the most sensitive indicators of toxicity.
46
And so we typically begin there.
47
Bruce Lamphere is a professor of health sciences at Simon Fraser University in Canada and studies environmental neurotoxins like lead, pesticides and mercury.
48
Some of the first studies to show a link between fluoride intake
49
and IQ were from villages in China with high natural amounts of fluoride starting in 1989 through the 2000s.
50
that children who grew up in a village where the water had high levels of fluoride and compared them to villages
51
Without high levels of fluoride.
52
They measured levels as high as 2 .3 gallons per swimming pool of water.
53
These early studies had plenty of issues, but they did raise a big red flag.
54
And what they found is comparing the high versus the low populations, they saw about a seven IQ point difference.
55
When it's that large, it's hard to sort of just dismiss.
56
For the average person, a few points difference in IQ doesn't have a huge impact, and it might not even be measurable.
57
The former director of the National Institute of Environmental Health Sciences explained this to me using lead as an example.
58
Thanks.
59
You can't prove that in an individual, but you look at a population.
60
And we know that if you shift the population's IQ, You have more people needing special services, you have fewer geniuses.
61
The results of those early studies inspired some researchers to try
62
and find out whether the neurological risk from high fluoride levels could also occur at lower levels, like the WHO maximum of 1 .5 milligrams per liter,
63
or even at the lower levels we fluoridate our water in the U .S.
64
Over the years, some studies have found an association between IQ and lower fluoride levels.
65
Some haven't.
66
Leaving scientists, particularly in the dental and epidemiological communities, divided on the issue. But
67
while we were working on this video, U .S federal scientists published a rigorous analysis of 74 of the studies on childhood IQ and fluoride.
68
In it, a small number of high -quality studies from outside the U .S found an association between lower IQ
69
and water fluoride levels below 1 .5 milligrams per liter.
70
But the small number of studies meant
71
that they weren't able to draw conclusions about the levels that we fluoridate water in the U .S.
72
I called Bruce Lanphier back up to make sense of the results.
73
Hello again.
74
The meta -analysis is really a way to synthesize
75
and quantify the high -quality studies and the low -quality studies and try to make sense of it.
76
Because otherwise, what you're left with is, well, these studies, which are my favorite studies, said this, and that confirms my belief.
77
And these studies, which did that, don't confirm my belief, and clearly they're wrong.
78
below 1 .5 milligrams per liter were associated with lower IQ,
79
translating to a loss of 1 .6 IQ points per 1 milligram per liter of fluoride in urine.
80
the totality of exposure that people have.
81
And that's how we measure risk.
82
From total exposure, not from one isolated source.
83
Bruce explained that the fluoride we put in our water is just the minimum amount of fluoride we all consume.
84
Black and green tea leaves have high fluoride content.
85
A variety of food like potatoes and canned shellfish has fluoride in it.
86
The pesticides on our food can have fluoride in it too.
87
We consume fluoride if we accidentally swallow toothpaste or mouthwash.
88
And the levels of fluoride we add to water also doesn't capture the roughly 3 million Americans, primarily in the southwest, that use groundwater
89
that has natural fluoride concentrations even higher than 1 .5 milligrams
90
per liter you Experts were particularly concerned about infants who drink formula.
91
Almost their entire diet is fluoridated water and dry formula that can have fluoride in it too.
92
And about pregnant people who can pass all of this fluoride intake to a fetus.
93
We oftentimes see exposures that exceed 1 .5, and in some cases in pregnant women during the third trimester.
94
We saw levels much higher.
95
So what do we make of all of this information?
96
First of all, topical fluoride is essential for keeping our teeth healthy.
97
And for non -pregnant adults, there is no evidence that ingesting fluoride is harmful.
98
There is some evidence that pregnant people, babies, and young children should be aware of their overall fluoride intake.
99
to feed their babies to make it with water that doesn't have fluoride on it.
100
But if we're trying to figure out whether we still need to keep fluoridating our water, or whether it's safe to do so as is, the science still isn't conclusive.
101
So it's a confusing time for understanding these risks and benefits.
102
I am a believer in the precautionary principle, which does not say you act in the absence of evidence.
103
It says you act in the presence of concerning evidence.
104
And my reading of the literature is that there is enough data to say there is concern.
📺 Gleicher Kanal
B21
Sen. Murphy vs. Trump's corruption | Today, Explained
Daily ConversationWorking Adults
B26
Five things you need to know for the 2026 midterms | America, Actually
Business EnglishDaily ConversationUniversity Students
B24
Why are weddings so damn expensive?
Business EnglishDaily ConversationUniversity Students
B21
Are headphones destroying our hearing?
Daily ConversationUniversity StudentsWorking Adults
C11
How to be less neurotic | The Gray Area
Daily ConversationUniversity StudentsWorking Adults
B22
We’re already using AI more than we realize
Daily ConversationWorking Adults
B21
The Ticketmaster monopoly is over, now what?
Business EnglishDaily ConversationUniversity Students
B22
The biggest peach myth in America
Daily ConversationWorking Adults
B28
How to solve problems like a designer
Daily ConversationWorking Adults
B22
The origin of the '80s aesthetic
Daily ConversationUniversity StudentsWorking Adults
B217
Why “Buy one, get one free” isn’t a great deal
Business EnglishWorking Adults
B22
How F1 drivers survive their own cars
Business EnglishUniversity StudentsWorking Adults
B210
Why 350°F is the magic number for baking
Daily ConversationUniversity StudentsWorking Adults
B26
How did pink become a girly color?
Daily ConversationUniversity StudentsWorking Adults
B22
The real reason Boeing's new plane crashed twice
Business EnglishDaily ConversationUniversity Students
B21
Food waste is the world's dumbest problem
Business EnglishDaily ConversationUniversity Students
B21
Why AI art struggles with hands
Daily ConversationWorking Adults
B22
How the rich avoid paying taxes
Business EnglishDaily ConversationUniversity Students
B22
How Vladimir Putin won Republicans' approval
Daily ConversationWorking Adults
B25
Zohran Mamdani on his first priorities as NYC mayor (Full video interview)
Business EnglishDaily ConversationUniversity Students
✨ Empfohlenes Video
C14
25 Sätze
How Radioactive Are Your Teeth?
IELTS PrepTOEFL PrepUniversity Students
C15
75 Sätze
Why do we get Thirsty? | #aumsum #kids #education #science
IELTS PrepTOEFL PrepUniversity Students
C13
33 Sätze
Should social media platforms censor hate speech? | Nadine Strossen | Big Think
IELTS PrepTOEFL PrepUniversity Students
B22
31 Sätze
Mark Ruffalo on New York State's Environmental Leadership
IELTS PrepTOEFL PrepUniversity Students
B2193
28 Sätze
Why should we care about coral reefs?
IELTS PrepTOEFL PrepUniversity Students
C11
114 Sätze
Education in America
IELTS PrepTOEFL PrepUniversity Students
C11
284 Sätze
Why do people smoke?
IELTS PrepTOEFL PrepUniversity Students
C14
41 Sätze
The Building Blocks of Everything: Matter & its Properties
IELTS PrepTOEFL PrepUniversity Students
B111
24 Sätze
Phát âm chuẩn cùng VOA - Anh ngữ đặc biệt: New Food Safety Rules (VOA)
American AccentIELTS PrepTOEFL PrepUniversity Students
C143
96 Sätze
Milk. White Poison or Healthy Drink?
IELTS PrepTOEFL PrepUniversity Students
C13
259 Sätze
We've Been Using The Wrong Science In Court For 50 years
IELTS PrepTOEFL PrepUniversity Students
C126
62 Sätze
The use of soil to reduce carbon dioxide in the atmosphere | IELTS LISTENING TEST | SECTION-4
IELTS PrepTOEFL PrepUniversity Students
Kontext & Hintergrund
In diesem Video wird das Thema Fluorid im Trinkwasser behandelt, insbesondere die Auswirkungen auf die Mundgesundheit. Der Sprecher erläutert, wie Fluorid Karies vorbeugt, indem es den Zahnschmelz remineralisiert und als Schutzbarriere gegen die Säuren von Bakterien im Mund wirkt. Viele Amerikaner trinken fluoridhaltiges Wasser, jedoch gibt es auch eine Debatte über die Sicherheit und Notwendigkeit der Fluoridierung. Wissenschaftler untersuchen, ob die empfohlene Dosierung von Fluorid in unserem Wasser für die Gesundheit von Kindern geeignet ist, insbesondere in Bezug auf die Entwicklung des Gehirns. Dieser Hintergrund eignet sich bestens für Lernende, die ihr Englisch verbessern möchten, insbesondere im Hinblick auf Themen der öffentlichen Gesundheit.
Top 5 Phrasen für die tägliche Kommunikation
- „Fluorid ist wichtig für die Mundgesundheit.“
- „Es schützt uns vor Karies.“
- „Die Wissenschaft über Fluorid entwickelt sich weiter.“
- „Wie viel Fluorid ist sicher?“
- „Studien zeigen unterschiedliche Ergebnisse.“
Schritt-für-Schritt Shadowing-Anleitung
Um die im Video besprochenen Konzepte besser zu verstehen und Ihre Sprechfertigkeiten zu verbessern, empfiehlt es sich, die Technik des Shadow Speak anzuwenden. Hier ist eine Schritt-für-Schritt-Anleitung:
- Hören Sie aktiv zu: Beginnen Sie damit, das Video ohne Untertitel anzusehen, um ein Gefühl für die verwendete Sprache und den Tonfall zu bekommen.
- Kurze Abschnitte wiederholen: Stoppen Sie das Video oft nach ein oder zwei Sätzen. Versuchen Sie, das Gehörte laut nachzusprechen, um Ihre Aussprache und Intonation zu verbessern. Dies ist eine effektive Methode des shadowspeaks.
- Verstehen Sie den Inhalt: Achten Sie darauf, die Bedeutung der Schlüsselphrasen und den Kontext zu erfassen. Machen Sie Notizen, um wichtige Begriffe wie „Karies“ und „Mundgesundheit“ festzuhalten.
- Vergleichen Sie Ihre Aussprache: Hören Sie sich Ihre Wiederholungen an und vergleichen Sie sie mit der Originalaufzeichnung, um Bereiche zu identifizieren, in denen Sie sich verbessern können.
- Wenden Sie das Gelernte an: Nutzen Sie die neuen Phrasen in Gesprächen oder schriftlichen Übungen, um sicherzustellen, dass Sie sie im richtigen Kontext verwenden können.
Durch diese Methode des shadow speech können Lernende nicht nur ihre Sprachkenntnisse verbessern, sondern auch ein tieferes Verständnis für komplexe Themen entwickeln. Beginnen Sie mit diesem strukturierten Vorgehen und beobachten Sie, wie sich Ihre Fähigkeiten im Englischen weiterentwickeln. Ein gutes shadowing site wird Ihnen helfen, immer besser zu werden!
Grammatik in diesem Video
Die Strukturen, die der Sprecher am häufigsten verwendet, mit den genauen Worten aus dem Video:
| Struktur | Im Video |
|---|---|
| Relativsätze who / which + Satz – eine Zusatzinformation über eine Person oder Sache | cavities, which is · children who grew · studies, which are |
| Present Perfect have/has + Partizip Perfekt – eine vergangene Handlung, die jetzt noch wichtig ist | have stopped · we've learned · have found |
| Passiv be + Partizip Perfekt – wichtig ist, was geschieht, nicht wer es tut | being considered · were associated · is fluoridated |
Was ist die Shadowing-Technik?
Shadowing ist eine wissenschaftlich fundierte Sprachlerntechnik, die ursprünglich für die professionelle Dolmetscherausbildung entwickelt und durch den Polyglotten Dr. Alexander Arguelles populär gemacht wurde. Die Methode ist einfach aber wirkungsvoll: Du hörst englisches Audio von Muttersprachlern und wiederholst es sofort laut — wie ein Schatten, der dem Sprecher mit nur 1–2 Sekunden Verzögerung folgt. Anders als passives Hören oder Grammatikübungen zwingt Shadowing dein Gehirn und deine Mundmuskulatur, gleichzeitig echte Sprachmuster zu verarbeiten und zu reproduzieren. Studien zeigen, dass es Aussprachegenauigkeit, Intonation, Rhythmus, verbundene Sprache, Hörverständnis und Sprechflüssigkeit signifikant verbessert — was es zu einer der effektivsten Methoden für die IELTS Speaking-Vorbereitung und reale englische Kommunikation macht.