week 3 children's health

Question 1

What are factors that lead to the differences between adults and children related to environmental exposure?

Answer 1

Unique pathways, physiological differences, short stature, behavior, higher surface are to body mass ratio, higher dermal absorption, limited ability to sense danger

Question 2

What unique pathways for toxic exposure exist for fetuses/ infants?

Answer 2

Placenta and breast milk

Question 3

Is the placenta and effective barrier for toxins?

Answer 3

No, this is an outdated view

Question 4

What toxins can cross the placental barrier?

Answer 4

lead, mercury, PCBs, alcohol, toxins from cigarette smoke, methadone, iodizing radiation, heat

Question 5

What is thalidomide? What problems did it cause?

Answer 5

• Antinausea/sedative drug prescribe in ’50s in Canada and Europe
• result in limb malformations, heart, eye, and ear defects

Question 6

What is DES? What problems did it cause?

Answer 6

• prescribed tom 1940-1971 to prevent cancer
• found to be associated with rare form of cervical cancer & increase in preterm birth/miscarriage in women whose mothers took DES during pregnancy

Question 7

What toxins are passed through breast milk?

Answer 7

DDT, PCBs, dioxin, nicotine, lead, methyl mercury, alcohol (levels must be really high for negative health effects to be seen)

Question 8

What behaviors put children at risk for toxic exposure?

Answer 8

mouthing and pica

Question 9

What does an increased anabolic mode in infants and young children have to do with toxic exposures?

Answer 9

Higher anabolic mode due to growth means more exposure to toxins; higher respiration, higher rate of delivery of toxins ingested via food/water

Question 10

What biotransformative difference exist in infants?

Answer 10

• metabolic pathways are less efficient

- causes increased exposure duration and amount

Question 11

What distribution difference exists in infants/toddlers?

Answer 11

Blood-brain barrier not fully developed until age 3; permits toxins like lead to get into brain

Question 12

What elimination differences exist in in infants?

Answer 12

Kidney filtration is less than 40% of the rate in adults

Question 13

What organs/systems continue to develop/mature throughout adulthood?

Answer 13

brain & CNS, lungs, kidneys, reproductive organs, immune system, endocrine system

Question 14

What is the relationship between lung function and ozone?

Answer 14

• decreased growth/lung function among children exercising in high ozone areas
• 3X increase in risk of asthma for students athletes in high ozone areas

Question 15

Why are infants increasingly exposed to nitrates?

Answer 15

There has been in increase in nitrates in drinking H2O due to agricultural run-off and groundwater contamination

Question 16

Which group of infants have the highest exposure to nitrates?

Answer 16

Infants who are not exclusively breast fed

Question 17

Why is nitrate consumption bad?

Answer 17

Nitrates convert to nitrites in GI tract due to higher pH in infants gut, nitrites oxidize hemoglobin making it unable to carry O2, detoxification prevents this problem

Question 18

How can you prevent excessive nitrate consumption in infants?

Answer 18

Exclusive breastfeeding up to 6 months

Question 19

What paternal exposures can have a negative effect on children’s health?

Answer 19

Preconception exposures linked to spontaneous abortion/stillbirth: mercury, ethylene oxide, chemicals used to make rubber, solvents

Question 20

What paternal occupations have an increased risk for children’s health problems?

Answer 20

• painters: anencephaly
• vehicle mechanics/welders: Wilms’ tumor
• textile workers: stillbirth, preterm birth

Question 21

What maternal preconception exposures are harmful? How?

Answer 21

include PCBs, lead, low folic acid; linked to spontaneous abortions, stillbirth, children’s learning disabilities

Question 22

What maternal exposures in-utero are harmful? What health problems do they cause?

Answer 22

• X-rays & leukemia
• heat & neural tube defects
• alcohol & Fetal Alcohol Syndrome
• lead & neurodevelopmental effects
• PCBs & low birth weight, neurodevelopmental defects

Question 23

What does a longer life expectancy have to do with children and toxin exposure?

Answer 23

• when exposed early in life, there are more yrs for illness w/ long latency period to manifest
• once ill, there are more years of disability

Question 24

What childhood exposures can result in adult morbidity?

Answer 24

asbestos exposure causes asbestosis

lead exposure causes adult hypertension

Question 25

How can Parcelceus’ famous saying be adjusted for children’s health

Answer 25

the dose and the TIMING make the poison