Transcript Children are not little adults

TRAINING FOR THE HEALTH SECTOR
[Date …Place …Event…Sponsor…Organizer]
CHILDREN ARE NOT LITTLE ADULTS
Children's Health and the Environment
WHO Training Package for the Health Sector
World Health Organization
www.who.int/ceh
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Children are not little adults
CHILDREN NEED HEALTHY ENVIRONMENTS
 Health is more than absence of illness
 Children need healthy environments in which to grow
and develop, play and learn
 Adults must ensure that children are protected from
environmental threats
 Now and for generations to come!
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Children are not little adults
LEARNING OBJECTIVES
AFTER THIS PRESENTATION, INDIVIDUALS WILL BE ABLE TO:

List ways why risks to children from environmental hazards
are different from those for adults

Illustrate children’s increased and unique vulnerabilities to
environmental threats

Understand the relationship between children and the
environment – starting before conception and continuing
throughout development

Propose remedial and preventive actions
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Children are not little adults
CHILDREN ARE NOT LITTLE ADULTS
Giotto, National Gallery, Washington DC
Raphael, National Gallery of Art, Washington, DC
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Children are not little adults
CHILDREN ARE NOT LITTLE ADULTS
1. Different and unique exposures
2. Dynamic developmental
physiology
3. Longer life expectancy
4. Politically powerless
Raphael, National Gallery of Art, Washington, DC
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Children are not little adults
1. DIFFERENT AND UNIQUE EXPOSURES
 Unique exposure pathways
 Transplacental
 Breastfeeding
 Exploratory behaviours leading to exposures
 Hand-to-mouth, object-to-mouth
 Non-nutritive ingestion
 Stature and living zones, microenvironments
 Location – lower to the ground
 High surface area to volume ratio
 Children do not understand danger
 Pre-ambulatory
 Adolescence – “high risk” behaviours
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1. DIFFERENT AND UNIQUE EXPOSURES
TRANSPLACENTAL
Lessons from pharmaceuticals:
thalidomide, diethylstilbestrol (DES), alcohol
 Many chemicals cross the placenta
 Lead, mercury, polychlorinated biphenyls (PCBs)…
 Substances of abuse: alcohol, methadone
 Some physical factors may affect the fetus directly
EHP
 Ionizing radiation, heat
Maternal exposures do matter!
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Children are not little adults
1. DIFFERENT AND UNIQUE EXPOSURES
BREASTFEEDING
 Breast milk is the safest and most
complete nutrition for infants
 Mothers should avoid toxic exposures
 Milk (human, cow, sheep) can be a marker of
environmental contamination
 DDT, DDE, PCBs, TCDD (dioxins),
nicotine, lead, methylmercury, alcohol
WHO
 Morbidity rarely seen
 Unusual exposure event
 Mother also ill
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Children are not little adults
1. DIFFERENT AND UNIQUE EXPOSURES
BEHAVIOUR AND SOIL CONSUMPTION
400
350
mg/day
300
Child (mean)
250
Child (upper
percentile)
Adult
200
150
100
50
0
US EPA
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Children are not little adults
1. DIFFERENT AND UNIQUE EXPOSURES
STATURE AND BREATHING ZONES
Guzelian, ILSI, 1992
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Children are not little adults
1. DIFFERENT AND UNIQUE EXPOSURES
STATURE AND BREATHING ZONES
WHO
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Children are not little adults
1. DIFFERENT AND UNIQUE EXPOSURES
SIZE AND SURFACE AREA
0.07
0.06
0.05
Newborn
Toddler
Child
Adult
0.04
0.03
0.02
0.01
0
Surface Area/Body Mass
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Children are not little adults
1.
DIFFERENT AND UNIQUE EXPOSURES
CHILDREN / ADOLESCENTS DO NOT RECOGNIZE DANGER
 Pre-ambulatory children are unable to remove
themselves from danger
 Pre-reading children cannot read warning signs & labels
 Pre-adolescent / adolescent children may take
unreasonable risks due to cognitive immaturity and
"risk-taking" behaviours
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
MORE VULNERABLE
Xenobiotics may be handled differently by an immature body
 Increased energy, water and oxygen
consumption of anabolic state
 Absorption
 Biotransformation
 Distribution
 Elimination
 Critical windows of development
WHO
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
OXYGEN DEMAND
Minute ventilation per kg body weight/day
600
500
400
300
litres/kg/day
200
100
0
<1
4
12
Age in years
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Miller, Int J Toxicology (2002) 21(5);403
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
CALORIE AND WATER NEEDS
Maintanencerequirements
Requirements
Maintenance
cal/kg/day
ml/kg/day
180
160
<1
1.0-3.0
4.0-6.0
7.0-10.0
11.0-14
15-18
19-24
25-50
50+
140
120
100
80
60
40
20
0
Calories
Water
Age in Years
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2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
ABSORPTION
A child is building a “body for a lifetime”
The demands of rapid growth and development
 Require higher breathing rate, caloric and water intakes
 Satisfied by enhanced absorption and retention of nutrients
For example:
GI absorption of lead in toddler: 40–70% of oral dose (1/3 retention)
GI absorption of lead in non-pregnant adult: 5–20% (1% retention)
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
LESSONS LEARNED FROM PHARMACEUTICALS
T1/2 40 Substrate database
***P < 0.001
Ginsberg,Toxicol Sci (2002)66(2):185
Pre-term
FT
1w–2m
2–6m
6m–2y
2–12y
12–18y
 In the aggregate, slower elimination in the very young
 No statistical difference after 2 months
 Children’s PK Database (www.clarku.edu/faculty/dhattis)
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2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
LESSONS LEARNED FROM PHARMACEUTICALS
T1/2 18 substances involving CYPs
*P<0.05, **P<0.01, ***P<0.001, ****P<0.0001
Ginsberg,Toxicol Sci (2002)66(2):185
Preterm
FT
1w–2m
2–6m
6m–2y
2–12y
12–18y
 More differences for substances predominantly metabolized by P450 enzymes
in liver
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
LESSONS LEARNED FROM PHARMACEUTICALS
T1/2 CYP1A2 substrates-caffeine, theophylline
#, SE = 21.63. *P < 0.1; **P < 0.05;
***P < 0.01; ****P < 0.0001
Ginsberg,Toxicol Sci (2002)66(2):185
FT
1w–2m
2–6m
6m–2y
2–12y
 High variability even for closely related drugs
 Neonate/adult difference for caffeine 13X greater than for theophylline
Generalizations are not possible!
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
NITRATES AND METHAEMOGLOBINAEMIA
Special problem for infants
 Increased exposure from contaminated well-water
 Increased “activation” as nitrates convert to nitrites (gut pH)
 Increased toxicity: fetal haemoglobin more easily oxidized
 Decreased “detoxification”: 50% capacity of NADH-dependent
reductase
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
WINDOWS OF DEVELOPMENT
Moore, Elsevier Inc, 1973
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
WINDOWS OF DEVELOPMENT: FATHERS AND THEIR OFFSPRING
 Paternal exposure to:
Hg, ethylene oxide, rubber chemicals, solvents,
linked to spontaneous abortion
 Paternal occupation:
Painters – anencephaly
(Brender. Am J Epidemiol, 1990, 131(3):517)
Mechanics, welders – Wilms tumour
(Olshan. Cancer Res, 1990, 50(11):3212)
Textiles – stillbirth, pre-term delivery
(Savitz. Am J Epidemiol, 1989, 129(6):1201)
Possible mechanism: impairment of a paternal gene required for the normal
growth and development of the fetus
“The special and unique vulnerability of children to
environmental hazards” Bearer, Neurotoxicology, 2000, 21(6):925
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
WINDOWS OF DEVELOPMENT: MOTHERS AND THEIR OFFSPRING
Pre-conception
PCBs and Pb maternal body burdens are linked to
abortion, stillbirth and learning disabilities
Folate deficiency leads to neural tube defects
In utero
Thalidomide
DES
X-rays
Heat
Alcohol
Lead
Methyl mercury
PCBs
phocomelia
vaginal cancer
leukaemia
neural tube defects
FAS (fetal alcohol syndrome)
Neurodevelopmental effects
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
WINDOWS OF DEVELOPMENT: BIRTH TO ADOLESCENCE
 Vital organ growth




Brain
Lungs
Kidneys
Reproductive organs
 Physiological function
 Central nervous system
 Immune system
 Endocrine system
Altman eds, FASEB, 1962
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2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
NEURODEVELOPMENT: CONTINUES THROUGH PUBERTY!
 Growth 4–17 yrs
in fibre tracts for
motor and speech
 Activity alters
architecture
 Adolescence
extensive
elimination of
some synapses
 Redistribution of
neurotransmitters
Rice,EHP, (2000) 108 (3), 511
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
NEURODEVELOPMENT: CONTINUES THROUGH PUBERTY!
An example: activity alters
brain architecture
 Centre of cortical responsive to
tactile stimulation of the 5th
finger, left hand
 Violin players vs non-players
 Correlated with age of onset, not
amount of practice
Rice. Critical periods of vulnerability for the developing nervous system. EHP, 2000, 108 (3): 520
Toxic exposures also can alter brain architecture!
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
RESPIRATORY DEVELOPMENT: CONTINUES THROUGH LINEAR
GROWTH
Growth
•Tobacco smoke
• Particulates
• Ozone
10 X 106 Alveoli
Function
300 X 106 Alveoli
(age 8)
• Indoor air
• Ozone
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Dietetr,. EHP, 2000,108 (3): 483.
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
RESPIRATORY DEVELOPMENT: STUDIES SHOW
 Deficits in pulmonary function tests

Related to exposure to particulates, oxides of nitrogen
and inorganic acid vapours (Gauderman. Am J Respir Crit Care Med,
2000, 162: 1383)

Exposure to secondhand tobacco damages pulmonary
function (Tager. N Engl J Med, 1983, 309 (12): 699)
 “Dirty air stunts growth”

Study of 3000 children since 1993 showed impaired lung
growth…may be linked to asthma and emphysema in
adults (Gauderman. Am J Respir Crit Care Med, 2000, 162: 1383)
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Children are not little adults
2. DYNAMIC DEVELOPMENTAL PHYSIOLOGY
RESPIRATORY DEVELOPMENT: AMBIENT OZONE AND ASTHMA
Relative Risk of Asthma
* 3.3 (1.9-5.8)
3.5
3
2.5
2
1.5
1
0.5
0
High Ozone
0
1
2
3+
Number of
Sports
Low Ozone
McConnell, Lancet (2002)359(9304):386
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3. LONGER LIFE EXPECTANCY
 Exposures early in life permit
manifestation of environmental
illnesses with long latency periods
 More disease
 Longer morbidity
WHO
Children inherit the world WE make!
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Children are not little adults
3. LONGER LIFE EXPECTANCY
Two examples:
 Asbestos exposure in children and cancer many years
after it
 Childhood exposure to lead and its relationship with
adult hypertension and mortality
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Children are not little adults
4. POLITICALLY POWERLESS
 No political voice
 Advocacy by health sector
by Ceppi and Corra
 Environmental laws and
regulations
 Local
 National
 International
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Children are not little adults
CHILDREN ARE NOT LITTLE ADULTS
1. Different and unique
exposures
2. Dynamic developmental
physiology
3. Longer life expectancy
4. Politically powerless
Raphael, National Gallery of Art, Washington, DC
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Children are not little adults
COMPLEX ENVIRONMENT OF CHILDREN AND
ADOLESCENTS
SETTINGS
HAZARDS
Physical
Chemical
MEDIA
Water - Air - Food - Soil - Objects
Biological
ACTIVITIES
Learning, Working, Eating, Drinking, Sleeping, Breathing, Smoking,
Doing sports, Playing, "Testing", Scavenging
Rural/urban
Home
School
Playground
Sports place
Field/Street
Public places
Workplace
OUTCOME-EFFECTS
SUSCEPTIBILITIES
Critical windows/timing
Age
Nutritional status
Poverty
Photo credit US NIEHS CERHR logo
– good or bad?
Organs
Systems
Functions
Development
Survival
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CRITICAL ROLE OF HEALTH AND
ENVIRONMENT PROFESSIONALS
 Diagnose and treat
 Publish, research
 Sentinel cases
 Community-based interventions
WHO
 Educate
 Patients and families
 Colleagues and students
 Advocate
 Provide good role model
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Children are not little adults
We hold our future in our hands
and it is our children
Poster Contest by HRIDAY with support from WHO SEARO
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Children are not little adults
POINTS FOR DISCUSSION
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Children are not little adults
ACKNOWLEDGEMENTS
WHO is grateful to the US EPA Office of Children’s Health Protection for the
financial support that made this project possible and for some of the data, graphics
and text used in preparing these materials.
First draft prepared by Katherine M. Shea MD MPH, USA
With the advice of the Working Group on Training Package for the Health
Sector: Cristina Alonzo MD (Uruguay); Yona Amitai MD MPH (Israel);
Stephan Boese-O’Reilly MD MPH (Germany); Irena Buka MD (Canada);
Lilian Corra MD (Argentina) PhD (USA); Ruth A. Etzel MD PhD (USA); Amalia
Laborde MD (Uruguay); Ligia Fruchtengarten MD (Brazil); Leda Nemer TO
(WHO/EURO); R. Romizzi MD (ISDE, Italy); S. Borgo MD (ISDE, Italy)
Reviewers: G. Tamburlini (Italy); I. Makalinao MD (Philippines), I. Buka MD
(Canada), R. Etzel MD (USA)
Update: July 2008
WHO CEH Training Project Coordination: Jenny Pronczuk MD
Medical Consultant: Katherine M. Shea MD MPH USA,
Technical Assistance: Marie-Noel Bruné MSc
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Children are not little adults
DISCLAIMER
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letters.
The opinions and conclusions expressed do not necessarily represent the official position of the World Health
Organization.
This publication is being distributed without warranty of any kind, either express or implied. In no event shall the
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damages, arising out of the use of this publication
The contents of this training module are based upon references available in the published literature as of the
last update. Users are encouraged to search standard medical databases for updates in the science for issues
of particular interest or sensitivity in their regions and areas of specific concern.
If users of this training module should find it necessary to make any modifications (abridgement, addition or
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Organization disclaims all responsibility for adaptations made by others. All modifications shall be clearly
distinguished from the original WHO material.
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