Children, Health, and the Environment

1
Children, Health, and the Environment

• K.C. Donnelly
• Department of Environmental Occupational
  Health
• School of Rural Public Health
• Texas AM University System Health Science Center

2
Children Smiles!
3
Objectives

• Define Environment
• Are children vulnerable receptors?
• Discuss specific environmental hazards (e.g.,
  lead, pesticides, asthma)
• Health promotion prevention.

4
Define Environment

• Air
• Water
• Soil
• Food
• Etc.

5
What is environmental health?
6
Are Children Small Adults?
7
Children as sensitive receptors
8

• A little kid goes from a single cell to a
  laughing, sociable, intelligent, friendly human
  being over the course of two years thats
  dramatic growth and development K. Olden

9
Exposure Birth Defects

• Pre-conception sterility
• First trimester spontaneous
  abortion
• First trimester major
  malformations
• Second trimester minor defects
• 0-9 months growth retardation delayed
  development

10
Development in the Newborn

• Nervous
• Respiratory
• Reproductive
• Immune
• Metabolic

11
Young children

• More than double their weight during first four
  months
• Breath more rapidly (and take in more air/unit
  body weight) than adults
• Have higher metabolic rates than adults

12
Behavioral characteristics

• Diet
• Hand-to-mouth activities
• Crawling
• Outside activities

13
Behavioral habits
14
Childrens Exposure Related Activities
15
How do environmental chemicals affect health?
16
What factors affect how our body reacts to a
chemical?

• Dose the amount of chemical that our body is
  exposed to.

• Duration the length of time our body is exposed
  to the chemical

17
Route

• Based on chemical properties, the route of
  exposure largely defines the amount of absorption.

• Dermal
• Ingestion
• Inhalation
• Injection

18
Assumptions

• Water 2 L per day
• Air 20 m3 per day
• Soil 200 mg per day (children)
• Food fruits vegs, milk, meat

19
How does the chemical move through out our body?

• Distribution is the process by which nutrients
  and substances move through out the body.

20
What happens to a chemical in the body?

• Metabolism is the process that increases the
  solubility of a chemical makes it easier to
  excrete

Metabolic activation
Benzo(a)pyrene-7,8-diol-9,10-epoxide
21

The environment can affect us in different ways.

• Industry and workplace pesticides, toxic waste,
  gasoline and solvents,
• Example The pesticides sprayed on farm crops can
  affect migrant workers and their families living
  closely.

22
The environment can affect us in different
ways.

• Environmental hazards chemical substances
  present in the air, water, soil, and food that
  negatively impact human, ecological, or animal
  well- being.

23
How does the environment affect us?

• Chemical Hazards chemical substances, such as
  pesticides, car batteries, and motor oil.

• Biological Hazards include microorganisms such
  as bacteria, viruses, and fungi.

• Physical Hazards radon, UV radiation or
  direct physical hazards for injury.

24
These hazards can also interact?

• Chemical Hazards may suppress the immune system.

• Biological Hazards several viruses bacteria
  have been associated with different cancers.

• Physical Hazards may increase permiability of
  the skin.

25
Example

• Exposure to cigarette smoke UV light has been
  observed to result in an increased risk of skin
  cancer.
• Why?

26
Does the environment affect health?

• WHO (2004)
• gt5,000,000 children die each year from
  environment-related illnesses

27
Do environmental chemicals affect US?

• 1973-1995 childhood brain nervous cancers
  increased 53
• 1966-1997 autism in the US doubled
• 1982-1994 asthma in children increased by more
  than 72

28
Developmental and Neurological Toxicity

• The Mad Hatter
• Lewis Carrolls Mad Hatter character in Alices
  Adventure in Wonderland probably is based on
  observations of the neurotoxic effects of
  inhaling vapors from mercury that nineteenth
  century hat-makers used to prepare felt.

29
Specific Environmental Hazards

• Lead
• Pesticides
• Air pollution Environmental tobacco smoke

30
LEAD
31
Lead (NHANES, CDC)

• 930,000 preschool children BLL gt 10 µg/dL
• 275,000 gt 15 µg/dL
• 85,000 gt 20 µg/dL

32
Blood Lead Levels in Residents of Homes with
Elevated Lead in Tap Water --- District of
Columbia, 2004 In March 2003, DC Water and
Sewer Authority (WASA) expanded its lead-in-water
testing program to homes with lead service pipes
extending from the water main to the house. By
late January 2004, results of the expanded water
testing indicated that the majority of homes
tested had water lead levels above EPA's action
level of 15 parts per billion (ppb). MMWR, March
2004
33
Sources of Lead Exposure

• Water
• Paint chips, soil
• Candy
• Food, food containers (ceramic)
• Air (reduced since elimination of unleaded
  gasoline)
• Other

34
Lin et al. (Am Jour Epi., 1998)

• 11 year study of exposed non-exposed workers in
  New York
• Workers who had elevated blood lead for more than
  5 years had a higher risk of low birth weight
  children (RR3.85) or premature birth (RR2.45)

35
Chiodo et al., (Neurotox Teratol., 2004)

• Sample of 246 inner-city children
• Consistently observed deficits in intelligence,
  reaction time, visual-motor integration others
  at blood lead levels between 5 and 10 µg/dL.
• Associations found at lead levels as low as 3
  µg/dL.

36
Lead Neurobehavioral Development

• Study of 294 children w/ BLL lt10 ug/dL at 12 and
  24 months
• Mental Psychomotor development significantly
  correlated with BLL.

Tellez-Rojo et al., 2007 Pediatrics
(118)2e323.
37
Lead Neurobehavioral Development

• Study of 174 children 60-month BLL DRD4
  polymorphisms
• DRD4 (dopamine receptor) polymorphism associated
  with poor spatial working memory, BLL impaired
  rule learning planning

Froehlich et al., 2007 Biol. Psychiatry Jan,
2007
38
Environmental Toxicants ADHD

• Prenatal tobacco exposure (OR2.5)
• Elevated blood lead (OR4.1)
• Postnatal tobacco exposure (OR0.6)
• Estimate that in US excess ADHD 270,000
  (prenatal tobacco), 290,000 (lead)

Braun et al., 2006 Environ Health Perspectives
39
Pesticides
40
Classes of Pesticides

• OCs
• OPs
• Carbamates
• Pyrethroids
• Etc.

41
Sources of Exposure

• Food
• Air Dust
• Water
• Household use misuse
• Other

42
OCs

• DDT, chlordane, heptachlor others
• Banned in U.S.
• Still available in some countries or from old
  stock.

43
OPs

• Malathion, parathion, chlorpyrifos, etc.
• Acute exposure produces SLUD
• Chronic, low-dose effects unknown

44
Pesticides Used in Texas
45
Pyrethroids

• Most common household pesticide
• Primary effect contact dermatitis
• May also exacerbate asthma

46
Levels of Pesticides in Urine by Age (Texas
colonias)
47
Total OP Metabolites in Urine (children 6-48
months)
48
(No Transcript)
49
Health Effects of Pesticides

• Children develop leukemia three to nine times
  more often when pesticides are used around their
  homes.
• Brain tumors and other cancers in children have
  been linked with exposures to insecticides.
• EPA estimated that as much as 75 percent of
  household pesticide use is inside the home and 22
  percent is in yards and gardens.

50
Health Effects of Pesticides

• Little is know regarding the effects of long-term
  exposure to low doses of pesticides.
• Likely to be genetic sensitivities.

51
Conclusions

• Pesticide Levels in Homes Change During the Year
• Some Pesticides Stick to Childrens Hands more
  than others
• Pesticides Levels on Childrens Hands can be
  Higher than Levels in House dust

52
Decreasing Childrens Exposures

• Never use pesticides labeled for agricultural use
  in the home!
• Try harder to wash childrens hands before they
  eat.

53
Decreasing Childrens Exposures

• Wet mop floors where children play.
• Use caution when using pesticides on pets or in
  garden

54
Environment Respiratory Disease
55
Asthma

• Inflammation of airways
• Produced by allergy, viral infections airborne
  irritants (among others)
• Genetic component, 75-80 of children w/ asthma
  have significant allergies

56
XPD gene

• XPD (ERCC2) gene protein - 2 major roles
• ATP dependent DNA helicase involved in excision
  repair
• Initiation of RNA transcription by RNA polymerase
  II

57
C-alelle of XPD-6 confers some protection against
bronchitis in early childhood (800 children)
Bronchitis ever diagnosed ( first 2 years)
(Data from Topinka, Sram et al., 2006)
58
Conclusions

• Children with the XPD-6 AA genotype experienced
  bronchitis more frequently than children carrying
  C-alelle
• In addition to cancer susceptibility XPD may play
  a role in immune competence

• (Data from Topinka, Sram et al., 2006)

59
Improve your health through prevention
60
Risk Assessment

• Hazard Identification
• Dose-Response Assessment
• Exposure Assessment
• Risk Assessment

61
Risk Management

• Control of the source
• Control along the path
• Control at the level of the person
• Secondary prevention (i.e., detection, treatment)

62
Health Promotion

• Individual
• Interpersonal (e.g., family groups)
• Organization
• Community
• Society

63
Health Education Program

• Objective
• To deliver health education modules to families
  in Texas colonias assess behavioral changes.

64
Paso 2 COEP desarrolla los entrenamientos
necesarios
Paso 3 Los profesores de CERH/COEP entrenarán
promotoras (pre-post evaluacíon)
Paso 1 Reunión con la comunidad para identificar
temas de interés
Acercamiento a la Comunidad
Paso 6 Repasar módulos y corregir intervenciones

Paso 4 Cada promotora ofrece entrenamiento a 33
familias (pre-post evaluación)
Paso 5 Revisión de resultados y desarrollo de
intervenciones adecuadas
65
Conclusions
66
Protecting children from environmental risks -

• Help children breath easier
• Dont smoke
• Keep house clean
• Limit outdoor activity on ozone alert days

67
Protecting children from environmental risks -

• Protect children from lead poisoning
• Have children tested for lead
• Test home for lead in paint if built before 1978
• Wash hands frequently
• Do not use first draw water

68
Protecting children from environmental risks -

• Keep toxic chemicals away from children
• Store food trash in closed containers
• Follow directions on product labels
• Wash fruits vegetables
• Store toxic chemicals out of reach

69
Protecting children from environmental risks -

• Protect children from too much sun
• Wear hats protective clothing
• Use sunscreen w/ SPF 15
• Keep infants out of direct sunlight
• Limit time in sun between 10 am 4 pm

70
Acknowledgements

• NIEHS Superfund Basic Research Program Grant No.
  
• USEPA Childhood Exposure to Pesticides Grant No.
• STEER (UT HSC SA Joan Englehardt, Roger
  Perales)
• Promotoras of the Sisters of Mercy (Sandra
  Contreras, Hermalinda Tamez, Carmen Rodriguez)

71
Childrens Environmental Health Websites

• www.cehn.org
• www.neihs.nih.gov/kids/home.htm
• www.epa.gov/region6/6pd-t-kid/children.htm
• http//yosemite.epa.gov/ochp/ochpweb.nsf/homepage