week 3 children's health Flashcards
What are factors that lead to the differences between adults and children related to environmental exposure?
Unique pathways, physiological differences, short stature, behavior, higher surface are to body mass ratio, higher dermal absorption, limited ability to sense danger
What unique pathways for toxic exposure exist for fetuses/ infants?
Placenta and breast milk
Is the placenta and effective barrier for toxins?
No, this is an outdated view
What toxins can cross the placental barrier?
lead, mercury, PCBs, alcohol, toxins from cigarette smoke, methadone, iodizing radiation, heat
What is thalidomide? What problems did it cause?
- Antinausea/sedative drug prescribe in ’50s in Canada and Europe
- result in limb malformations, heart, eye, and ear defects
What is DES? What problems did it cause?
- 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
What toxins are passed through breast milk?
DDT, PCBs, dioxin, nicotine, lead, methyl mercury, alcohol (levels must be really high for negative health effects to be seen)
What behaviors put children at risk for toxic exposure?
mouthing and pica
What does an increased anabolic mode in infants and young children have to do with toxic exposures?
Higher anabolic mode due to growth means more exposure to toxins; higher respiration, higher rate of delivery of toxins ingested via food/water
What biotransformative difference exist in infants?
- metabolic pathways are less efficient
- causes increased exposure duration and amount
What distribution difference exists in infants/toddlers?
Blood-brain barrier not fully developed until age 3; permits toxins like lead to get into brain
What elimination differences exist in in infants?
Kidney filtration is less than 40% of the rate in adults
What organs/systems continue to develop/mature throughout adulthood?
brain & CNS, lungs, kidneys, reproductive organs, immune system, endocrine system
What is the relationship between lung function and ozone?
- decreased growth/lung function among children exercising in high ozone areas
- 3X increase in risk of asthma for students athletes in high ozone areas
Why are infants increasingly exposed to nitrates?
There has been in increase in nitrates in drinking H2O due to agricultural run-off and groundwater contamination
Which group of infants have the highest exposure to nitrates?
Infants who are not exclusively breast fed
Why is nitrate consumption bad?
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
How can you prevent excessive nitrate consumption in infants?
Exclusive breastfeeding up to 6 months
What paternal exposures can have a negative effect on children’s health?
Preconception exposures linked to spontaneous abortion/stillbirth: mercury, ethylene oxide, chemicals used to make rubber, solvents
What paternal occupations have an increased risk for children’s health problems?
- painters: anencephaly
- vehicle mechanics/welders: Wilms’ tumor
- textile workers: stillbirth, preterm birth
What maternal preconception exposures are harmful? How?
include PCBs, lead, low folic acid; linked to spontaneous abortions, stillbirth, children’s learning disabilities
What maternal exposures in-utero are harmful? What health problems do they cause?
- X-rays & leukemia
- heat & neural tube defects
- alcohol & Fetal Alcohol Syndrome
- lead & neurodevelopmental effects
- PCBs & low birth weight, neurodevelopmental defects
What does a longer life expectancy have to do with children and toxin exposure?
- 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
What childhood exposures can result in adult morbidity?
asbestos exposure causes asbestosis
lead exposure causes adult hypertension
