Syst Rev May 2022 PMID 35637522

The effect of lead exposure on IQ test scores in children under 12 years: a systematic review and meta-analysis of case-control studies.

Serve Heidari, Shayan Mostafaei, Nazanin Razazian, Mojgan Rajati, Anahita Saeedi, Fatemeh Rajati

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Mentions

36
Peak: 5 in Apr 2024
across 4 sources since Oct 2022

Extended reach

58,028
potential audience

Total likes

61

Video views

1,100

Mentions per month

Oct 2022 – Oct 2025

Where it's discussed

  • X / Twitter24 posts
  • News8 articles
  • YouTube2 videos
  • Reddit2 posts

AI synopsis

What people are saying

Discussions illustrate a high level of interest and engagement, with many posts citing specific details from the study, such as the average IQ reduction of around 7.8 points due to lead exposure, and emphasizing its serious implications. The tone varies from supportive acknowledgment to skepticism, reflecting both recognition of the study’s importance and potential political or social narratives around environmental health issues.

AgreementModerate agreement

Most discussions acknowledge the study’s findings, with many referencing the link between lead exposure and reduced IQ, though some express skepticism or political opinions.

InterestHigh interest

Posts show high interest, especially when discussing the implications of lead poisoning on children's mental development and societal outcomes.

EngagementHigh engagement

Several contributions delve into specifics, questioning study methods, emphasizing the significance of the findings, and referencing related research to deepen the discussion.

ImpactModerate impact

While some posts highlight the broad societal consequences, others focus on the potential controversy or political misuse, indicating moderate perceived impact.

Abstract in brief

  • Lead exposure in children under 12 significantly lowers IQ scores, with the impact depending on both the level and duration of exposure.
  • The study reviewed data from 8 case-control studies involving 3,316 children, comparing those exposed to high lead levels (above 10 µg/dL) versus lower levels.
  • Longer exposure durations (more than 45 years) result in a greater reduction in IQ scores, emphasizing that both the amount and length of lead exposure can cause lasting damage to children's mental development.]

Top posts

Most liked on X and Bluesky
GCU Wandering Somnambulist
@SurlyWanderer · X

@UncleScottiepoo @KrisKobach1787 Republicans need people with lead poisoning otherwise their voter base disappears. https://t.co/OP01FKbOWW

Mar 8, 2024 · 43 likes · 2 shares · 79 followers View post →
Holtz
@Biorealism · X

@buzzingbeetome @eyeslasho So children with cognitive damage due to lead exposure as indicated by IQ scores don't have anything to worry about? How absurd. Psychometric testing is one thing in psychology that appears robust and with external validity across groups. https://t.co/BFwsN0DMJA

Oct 4, 2024 · 4 likes · 8,939 followers View post →
(Sichu Lu(Sichu.Lu218@proton.me)
@lu_sichu · X

@cremieuxrecueil https://t.co/LbHnfgYl7v here.

Aug 19, 2024 · 2 likes · 3,253 followers View post →
Thenameevaporated
@Whenitrains_961 · X

@eyeslasho @KaiKish_ https://t.co/0bUoE24WjR

Nov 13, 2023 · 2 likes · 1 share · 170 followers View post →
Susan G., PhD
@swarau · X

@Edgar_OE @mx__chichi Other studies show lead has negative effects on IQ. Example here: "This study demonstrates that the concentration and duration of lead exposure have a large effect on mental function in children." https://t.co/Chp1tlQV2X

Apr 2, 2024 · 1 like · 1 share · 1,014 followers View post →
Pilirin
@Jeff_pyrotek · X

@AsTimeGoesBy0 @davidbewart remember leaded petrol? https://t.co/KUgvD5u7jz

Feb 3, 2024 · 1 like · 230 followers View post →

All mentions

Neeko
@NeekoC18 · X

@Pablo01618 @FemaleMenaces @zerohedge I love the fact that when right over your head and you tripled down like an idiot for everyone to see. The effect of lead exposure on IQ test scores in children under 12 years: a systematic review and meta-analysis of case-control studies - PMC https://t.co/9llpFPbC8o

Sep 6, 2025 · 2,103 followers View post →
Ronald M. Chavin
@rmchavin · X

Iran & Sweden: We compared the IQs of kids with Pb >10μg/dL versus kids with Pb <10μg/dL https://t.co/2lhD8wLe8Z https://t.co/koszD1S984 https://t.co/5S1KIbOXfd https://t.co/nsnsHofwdb https://t.co/eL1OMSrj81 https://t.co/NUIwT45EnZ https://t.co/Kf9y5j1t3S https://t.co/17DrRZtw8x

Aug 25, 2025 · 214 followers View post →
Roger Staubach
@staubach46444 · X

@cremieuxrecueil That’s certainly a take. Here’s a quality meta analysis if you care to retract. https://t.co/v3QdPTfNgR

Mar 20, 2025 · 1 like · 58 followers View post →
Guy Incognito
@GuyIncognitoGuy · X

@UmBencaoCadaDia @vanillaopinions Here's a study directly linking lead poisoning and IQ https://t.co/GyDxaiaRGH https://t.co/HoYfKOm3hx

Nov 6, 2024 · 59 followers View post →
Holtz
@Biorealism · X

@buzzingbeetome @eyeslasho So children with cognitive damage due to lead exposure as indicated by IQ scores don't have anything to worry about? How absurd. Psychometric testing is one thing in psychology that appears robust and with external validity across groups. https://t.co/BFwsN0DMJA

Oct 4, 2024 · 4 likes · 8,939 followers View post →
(Sichu Lu(Sichu.Lu218@proton.me)
@lu_sichu · X

@cremieuxrecueil https://t.co/LbHnfgYl7v here.

Aug 19, 2024 · 2 likes · 3,253 followers View post →
SamBam
@sambam_at · X

@cerflerg @AverageSteveS @BronskiJoseph I’m not sure how you could say something so wrong with so much confidence. https://t.co/ufYjzQvUm6

Jul 19, 2024 · 515 followers View post →
Name can't be blank
@HabsAddictMtl · X

@booriley0 @DINKLEBERG_AF1 @groipa @atrupar @HughJaynus420 Just lead exposure reduced IQ by 7.8pts on average. https://t.co/1Fgl1HR1in

Jun 6, 2024 · 123 followers View post →
Holtz
@Biorealism · X

@Simonjenkin To an extent although if this were all tests measured then what is the point of studies showing cognitive impairment from childhood lead exposure based on these tests? https://t.co/obFAgyp2yi

Apr 23, 2024 · 8,939 followers View post →
Holtz
@Biorealism · X

@LHCBMatt Not exactly true. Otherwise there would be no point in testing for cognitive impairment from head injury or lead poisoning. https://t.co/obFAgyp2yi

Apr 23, 2024 · 8,939 followers View post →
Holtz
@Biorealism · X

@ReplySide Helped quantify cognitive harm from lead exposure? Army has used them for decades. An extreme case is identifying whether inmates are exempt from capital punishment. https://t.co/BFwsN0DMJA

Apr 3, 2024 · 8,939 followers View post →
Sina Source
@mx__chichi · X

RT @swarau: @Edgar_OE @mx__chichi Other studies show lead has negative effects on IQ. Example here: "This study demonstrates that the c…

Apr 2, 2024 · 1 share · 8,484 followers View post →
Susan G., PhD
@swarau · X

@Edgar_OE @mx__chichi Other studies show lead has negative effects on IQ. Example here: "This study demonstrates that the concentration and duration of lead exposure have a large effect on mental function in children." https://t.co/Chp1tlQV2X

Apr 2, 2024 · 1 like · 1 share · 1,014 followers View post →
S. Schoening
@sestesch · X

@VicedRhino This is specifically malicious since it‘s known what lead poisoning does to intelligence, https://t.co/VTk2518Mue

Mar 9, 2024 · 39 followers View post →
OldTacosNewFish
@new_tacos · X

RT @SurlyWanderer: @UncleScottiepoo @KrisKobach1787 Republicans need people with lead poisoning otherwise their voter base disappears. htt…

Mar 8, 2024 · 2 shares · 179 followers View post →
John (He/Him)
@UnoriginalJohn · X

RT @SurlyWanderer: @UncleScottiepoo @KrisKobach1787 Republicans need people with lead poisoning otherwise their voter base disappears. htt…

Mar 8, 2024 · 2 shares · 142 followers View post →
GCU Wandering Somnambulist
@SurlyWanderer · X

@UncleScottiepoo @KrisKobach1787 Republicans need people with lead poisoning otherwise their voter base disappears. https://t.co/OP01FKbOWW

Mar 8, 2024 · 43 likes · 2 shares · 79 followers View post →
Pilirin
@Jeff_pyrotek · X

@AsTimeGoesBy0 @davidbewart remember leaded petrol? https://t.co/KUgvD5u7jz

Feb 3, 2024 · 1 like · 230 followers View post →
Fabbeyonddadancer
@HB__AUG31_FAB · X

RT @lmcsomewhere: @eyeslasho @KaiKish_ https://t.co/0bUoE24WjR

Nov 19, 2023 · 1 share · 1,940 followers View post →
Thenameevaporated
@Whenitrains_961 · X

@eyeslasho @KaiKish_ https://t.co/0bUoE24WjR

Nov 13, 2023 · 2 likes · 1 share · 170 followers View post →
Name can't be blank
@HabsAddictMtl · X

@YungEuropean @kilogolfsierra @UsingLyft @whstancil If the simple presence of lead in blood can lower the IQ by 7.8 points, then the whole gap is explained by environmental factor. The avergae IQ was 92.1 for blacks Americans in 2006 and 103 for whites, then there could be no gap explained by race https://t.co/1Fgl1HQtsP

Aug 11, 2023 · 123 followers View post →
Last-White-Rose
@robertsonbrand9 · X

@73RDARM @RonFilipkowski There is a scientific explanation available... https://t.co/caQbDIrfSR. https://t.co/Qlv1Q2h035

Jul 29, 2023 · 1,198 followers View post →
|Smedley Butler|Gerald Nye|Elaine Scarry|
@HistoryGonzo · X

@barndoorbanjo @SwipeWright Yikes. https://t.co/pHF36y0hKR

Apr 12, 2023 · 76 followers View post →
Ally Jonsson
@AllyJonsson · X

Higher blood lead levels result in a lower intelligence quotient, which results in less job opportunities & earning potential. https://t.co/hMUTraz5QF.

Nov 30, 2022 · 1,154 followers View post →