Document ZBVGyqgjO6p07bVDqzkVv4j9O

O ctober 28, 19$9 E f fe c t o f season and te m p eratu re on childhood plumbism. I t i s th o u g h t t h a t le a d p o iso n in g an c h ild r e n has, a marked seasonal d is trib u tio n w ith alm ost a l l of the cases occuidng be tween th e months o f May and O ctober. T h is sea so n al d i s t r i b u t i o n h as been found t o be tr u e in C in c in n a ti, B altim o re , S t. L o u is, New York, P h ila d e lp h ia , and Chicago. This in c re a se in le ad poisoning i n c h ild re n in th e warm w eath er months h a s been a t t r i b u t e d to v a r i ous f a c t o r s . Exposure to th e more in te n s e u l t r a v i o l e t r a d ia tio n from th e sun i n th e summer and th e r e s u l t i n g in c re a s e in V itam in D has been the fa c to r most prom inently im p licated . This i s suggested on th e b a s is t h a t V itam in D in c r e a s e s th e a b s o rp tio n of le a d from this i n t e s t i n e s . The i n t e r - r e l a t i o n s h i p s among calciu m , le a d , and phosphorus le v e ls in the blood p la y a ro le here a lso , d e ta ils of which need n o t be c o n sid e re d a t t h i s tim e , ` t i s known t h a t U.V. l i g h t " s e n s itiz e s " c i r c u l a t i n g p o rp h y rin s. Some in v e s t ig a to r s f e e l th a t t h i s s e n s itiz a tio n of th e c ir c u la tin g porphyrins i s one explana t i o n o f th e sudden o n s e t o f symptoms o f plumbism d u rin g th e warm months o f th e y e a r . The o th e r im p o rta n t en v iro n m en tal c o n d itio n which has been suggested i s the in c re ase in environm ental tem perature d u rin g th e summer m onths. Some e x p e rim e n ta l work in anim als has shown t h a t r a b b i t s , who were s u b je c te d t o 37C fo llo w in g a seven- wdek p e rio d of/ subcutaneous in je c tio n s o f le a d , d ie d w ith in 102 h o u rs, w hereas th o se s im ila r ly i n j e c t e d b u t k e p t a t room tem p eratu re su rv iv e d , ap d id c o n tr o l r a b b i t s 1a t 37C. , An ex am ination o f Dr. Hugo S m ith 's d a ta on ch ild h o o d plumbism ip C in c in n a ti sin c e 19/0 shows t h i s seaso n al incidence o f le a d p o iso n in g . A ll c a se s in h is s e r i e s f a l l - between th e months o f May and Octo b e r. However, th e re i s no d ir e c t c o rre la tio n between a given tem pera tu re and o n set of symptoms, nor hours .pf s o la r ra d ia tio n and -onset of Symptoms. A ll t h a t can be s a id a t p r e s e n t i s t h a t th e r e i s a sea so n al incidence of childhood plumbism and how 'tem perature and s o la r ra d ia tio n a f f e c t s t h i s - i s n o t known. In re g a rd to t h i s , I am i n te r e s t e d in see in g i f th e re i s a se a so n a l in c id e n c e o f t h i s d is e a s e in Los A ngeles. Dr. Smith does n o t know o f any re p o rts : on th e in c id e n c e o f ch ild h o o d plumbism from e i t h e r Los A ngeles o r Miami, b u t h as given me names o f p e d i a t r i c i a n s whom I can c o n ta c t in th e s e two a re a s .