TY  - CHAP
M1  - Book, Section
TI  - Pediatric Environmental Health
A1  - Holm, Stephanie M.
A1  - Miller, Mark D.
A2  - LaDou, Joseph
A2  - Harrison, Robert J.
Y1  - 2021
N1  - 
T2  - CURRENT Diagnosis & Treatment: Occupational & Environmental Medicine, 6e
AB  - Many  of  the  physical  differences  in  children  compared  to  adults  put  them  at  increased  risk  from  toxicants  in  their  environments.  Because  children  are  growing,  they  have  a  higher  metabolic  rate  relative  to  their  size  compared  to  adults.  For  this  reason,  children  consume  relatively  more  of  all  the  things  needed  to  sustain  life  and  growth;  they  eat  more  food,  drink  more  water,  and  breathe  more  air.  Children  thus  get  a  higher  exposure  per  kilogram  of  body  weight  to  many  pollutants.  Moreover,  children  have  a  higher  surface  area  to  body  mass  ratio,  so  their  potential  for  dermal  absorption  is  also  higher.  Children  are  also  at  risk  in  utero.  Toxicants  which  are  either  small  molecules  or  fat-soluble  cross  the  placenta  easily,  as  do  some  metals.  Children  also  have  longer  remaining  life  expectancy,  meaning  that  exposures  with  long  lead  times  before  disease  (such  as  many  carcinogens)  can  be  more  problematic  for  children,  who  are  more  likely  to  live  long  enough  to  experience  an  adverse  effect.  Finally,  crawling  on  the  floor  and  children’s  short  stature  can  increase  their  exposure  to  heavy  airborne  toxicants,  such  as  mercury,  which  will  be  concentrated  closer  to  the  ground,  in  children’s  breathing  zone.  Metabolism  of  many  pharmaceuticals  and  environmental  contaminants  differ  by  age.  Cytochrome  P450  (phase  1)  and  conjugating  (phase  2)  enzyme  development  during  early  life  can  result  in  slower  detoxification  and  clearance  of  many  chemicals  in  neonates  and  young  children.  For  example,  while  conjugation  by  some  UGT  enzymes  is  mature  by  2  months,  for  others  adult  activity  is  not  reached  until  puberty.  For  some  chemicals  the  metabolic  pathways  are  age  dependent;  for  example,  acetaminophen  is  metabolized  by  sulfation  rather  than  glucuronidation  in  the  neonate.  
SN  - 
PB  - McGraw Hill
CY  - New York, NY
Y2  - 2023/09/30
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1180882674
ER  -