TY  - CHAP
M1  - Book, Section
TI  - Health Significance of Metal Exposures
A1  - Grandjean, Philippe
A2  - Wallace, Robert B.
PY  - 2017
T2  - Maxcy-Rosenau-Last Public Health and Preventive Medicine, 15e
AB  - The  term  metal  has  important  meanings  in  physics  and  chemistry.  In  environmental  medicine,  arsenic  and  selenium  are  often  considered  part  of  the  metals  group.  Nutritionists  often  refer  to  trace  metals  as  those  constituting  less  than  1  g  of  the  human  body,  an  arbitrary  limit  which  would  exclude  iron.  Although  “toxic  metals”  is  a  common  term,  all  metals  may  actually  exert  toxic  effects,  and  the  dose  and  time  of  exposure  determines  whether  or  not  toxicity  ensues.  Frequently,  heavy  metals  (with  a  gravity  of  4  g/cm3  and  above)  are  considered  most  important  with  regard  to  adverse  health  effects.  This  belief  stems  from  the  observation  that  the  toxicity  of  the  metals  tends  to  increase  toward  the  right  and  bottom  of  the  periodic  table,  where  the  molecular  weight  of  elements  increases.  However,  increased  atomic  number  and  increased  gravity  are  of  little  medical  significance  and  would  not  account  for  the  toxic  potential  of  beryllium.  Instead,  the  relative  toxicity  on  a  molar  basis  would  seem  to  be  related  to  the  affinity  to  various  ligands  and  the  resulting  biochemical  activity.  On  the  basis  of  such  considerations,  metals  may  be  separated  into  hard  metals  (class  A),  with  a  lower  affinity  toward  sulfur  and  nitrogen  than  toward  oxygen,  and  the  soft  metals  (class  B),  where  the  opposite  is  the  case.1  Among  the  metals  considered  in  this  chapter,  aluminum  and  beryllium  belong  to  the  generally  less  toxic  class  A,  while  the  other  metals  are  either  borderline  or  class  B  metals.  
SN  - 
PB  - McGraw-Hill Medical
CY  - New York, NY
Y2  - 2024/04/19
UR  - accessbiomedicalscience.mhmedical.com/content.aspx?aid=1141969253
ER  -