Low level environmental lead exposure--a continuing challenge.
The current threshold for lead toxicity, defined as a blood lead level of 10 microg/dL, was adopted by the United States (US) Centers for Disease Control and Prevention (CDC) in 1991 and the World Health Organization in 1995. Since that time, adverse health outcomes at blood lead levels below this threshold have been well demonstrated. Most concern probably relates to children of pre-school age; an international pooled analysis has demonstrated lead-associated intellectual deficits at blood lead levels well below 10 microg/dL. In the case of adults, several convincing population studies have shown a positive association between blood lead and risk of death. The largest such study compared mortality information from participants with blood lead levels in the highest third of the blood lead distribution (3.6 microg/dL or greater) with those in the lowest third (less than 1.9 microg/dL). After adjustment for potential confounders, estimates of the excess risk were 25% for all cause mortality and 55% for cardiovascular mortality. The adverse consequences of lead exposure have no discernible blood lead threshold, implying there is no safety margin at existing exposure levels. Despite marked declines in population mean blood lead levels since 1980, low level environmental lead exposure remains a significant public health concern.
Rossi
Enrico
E
Department of Clinical Biochemistry, PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands, WA 6909, Australia. ric.rossi@health.wa.gov.au
Arch Environ Health. 1994 Sep-Oct;49(5):326-31
7944562
J Hum Hypertens. 2002 Feb;16(2):123-31
11850770
N Engl J Med. 1992 Oct 29;327(18):1279-84
1383818
Environ Health Perspect. 2006 Oct;114(10):1538-41
17035139
J Paediatr Child Health. 2008 Dec;44(12):722-6
19077066
JAMA. 1994 Jul 27;272(4):284-91
8028141
N Engl J Med. 2003 Apr 17;348(16):1517-26
12700371
Environ Res. 2006 Jan;100(1):100-14
16337847
Med J Aust. 1992 Oct 5;157(7):441-5
1406391
N Z Med J. 2005 Jul 29;118(1219):U1587
16059407
Environ Health Perspect. 1990 Nov;89:95-100
2088762
Pediatrics. 1980 Feb;65(2):226-31
7354967
JAMA. 1998 Dec 9;280(22):1915-9
9851476
Sci Total Environ. 2003 Feb 15;303(1-2):79-104
12568766
Am J Epidemiol. 2001 Jan 15;153(2):164-71
11159162
Lancet. 2001 May 26;357(9269):1660-9
11425371
N Engl J Med. 1990 Jan 11;322(2):83-8
2294437
Arch Intern Med. 2005 Oct 10;165(18):2155-61
16217007
J Paediatr Child Health. 1995 Aug;31(4):326-31
7576892
Pediatrics. 2005 Oct;116(4):1036-46
16199720
N Z Med J. 2006 May 05;119(1233):U1958
16680175
N S W Public Health Bull. 2003 Mar;14(3):52-4
12806418
N Engl J Med. 1992 May 7;326(19):1293-4
1560812
Environ Res. 2004 Nov;96(3):274-82
15364594
Pediatrics. 2004 Jul;114(1):19-26
15231903
Arch Intern Med. 2002 Nov 25;162(21):2443-9
12437403
Circulation. 2006 Sep 26;114(13):1388-94
16982939
Environ Health Perspect. 2005 Jul;113(7):894-9
16002379
Environ Res. 2005 Oct;99(2):177-94
16194668