Current Issue of JAMA: Lead Exposure From Candles

[Guest guest]

Published in the current " Journal of the American Medical Association "

The current issue [7/12/00] of <A

HREF= " http://jama.ama-assn.org/issues/v284n2/full/jlt0712-6.html " >JAMA</A> [J

ournal of the American Medical Association] is available on the internet

now. This is GREAT...And will finally acquaint the Medical Community to this

little known source of lead exposure. An Endocrinologist I met with this

past week had never heard of this, as a matter of fact nearly every

physician I've encountered in the last 2 or 3 years has been completely in

the dark about this ;c) hopefully this information in JAMA will shed some

light on this problem for mainstream health care providers ;c)

<A HREF= " http://jama.ama-assn.org/issues/v284n2/full/jlt0712-6.html " >Lead

Exposure From Candles</A>

[http://jama.ama-assn.org/issues/v284n2/full/jlt0712-6.html]

Research Letters

<A HREF= " http://jama.ama-assn.org/issues/v284n2/full/jlt0712-6.html " >Lead

Exposure From Candles</A>

To the Editor: Blood lead levels as low as 0.43 µmol/L (10 µg/dL) in children

can result in developmental and behavioral problems, including lower

intelligence.1 For this reason, lead has been restricted in paint and banned

in gasoline and vinyl miniblinds in the United States. However, most

physicians are probably unaware that household candlewicks may still include

lead as a stiffener. In 1974, the candle industry agreed with the Consumer

Product Safety Commission (CPSC) to voluntarily stop making candles with

lead-containing wicks. In February 2000, we conducted a systematic survey to

determine the prevalence of such candles. We also estimated atmospheric lead

levels produced by burning lead wick candles.

Methods

We purchased 1 of each type of candle with a metallic wick from 11 chain

stores and 1 dollar store in the Baltimore-Washington area and tested these

for lead by using inductively coupled plasma spectroscopy (R. J. Lee Group,

Inc, Monroeville, Pa). We then used these measured lead contents to estimate

the average 24-hour ambient air lead levels that would result from burning

these candles for 3 hours by solving the following rate equations:

(1) d l(t)/dt= -0.2 l(t) for 0t3 h

(2) d l(t)/dt=-0.2 l(t) for t>3 h

Here, 1(t) is the concentration of lead in a 51-m3 room as a function of

time, is the rate at which lead enters the room (micrograms of lead per

centimeter of wick [determined empirically] length of wick consumed per hour

[1.33 cm/hr] (written communication, K. Bridbord, MD, December 14, 1973)

fraction of lead vaporized [20%] 2, and 0.2 is the typical fraction of air

exchanged per hour in an energy-efficient home.3

Results

Eighty-six (30%) of the 285 types of candles contained metallic wicks and 9

of these (10%) contained lead, for an overall 3% lead-wick prevalence. Total

lead content per wick ranged from approximately 24,000 µg to 118,000 µg (<A

HREF= " http://jama.ama-assn.org/issues/v284n2/fig_tab/jlt0712-6_t1.html " >Table

1</A>) (33%-85% lead by weight). When the rate equations are solved, these 9

candles are calculated to result in average 24-hour air lead concentrations

ranging from 15.2 to 54.0 µg/m3, which is 10.1 to 36.0 times the US

Environmental Protection Agency standard of 1.5 µg/m3.

Comment

Because each 1-µg/m3 increase in ambient air lead concentration in this range

can increase a child's blood lead level by 0.22 µmol/L (5 µg/dL),4 chronic

exposure to only 1.5 µg/m3 could raise a child's blood lead level from 0.13

µmol/L (2.7 µg/dL) (the median for US children younger than 5 years)1 to 0.48

µmol/L (10 µg/dL), which is the upper limit recommended by the Centers for

Disease Control and Prevention. Thus, all 9 candles that we tested have at

least 10 times enough lead to achieve this increase.

We estimated that the candle containing the least lead would produce an

average air lead concentration of 30.6 µg/m3 during 3 hours of burning; a

6-year-old, inhaling 0.66 m3 of this air per hour during average daily

activity5 would exceed the CPSC's recommended daily lead limit for children

(15 µg) in 45 minutes.

According to the National Candle Association, $2.3 billion worth of candles

were projected to be sold in 1999, a figure that is increasing by 10% to 15%

annually.6 Physicians must warn patients that burning candles with

lead-containing wicks may cause lead poisoning and that there is no reliable

method to distinguish metallic candlewicks containing lead from those that do

not. Families exposed to candles with metallic wicks should have their blood

lead levels checked. Most importantly, the CPSC should ban and recall all

candles containing wicks with lead; we have recently filed a petition

requesting this (<A HREF= " http://www.citizen.org/hrg/PUBLICATIONS/1510.htm " >ht

tp://www.citizen.org/hrg/PUBLICATIONS/1510.htm</A>).

L. Sobel, MD, MPH, MS

Lurie, MD, MPH

Sidney M. Wolfe, MD

Public Citizen's Health Research Group

Washington, DC

1. Centers for Disease Control and Prevention. Update: blood lead

levels—United States, 1991-1994. MMWR Morb Mortal Wkly Rep. 1997;46:141-146. <

A

HREF= " http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?db=m & form=6 & Dopt=r & u

id=9072671 " >MEDLINE</A>

2. van Alphen M. Emission testing and inhalational exposure-based risk

assessment for candles having Pb metal wick cores. Sci Total Environ.

1999;243-244:53-65. <A

HREF= " http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?db=m & form=6 & Dopt=r & u

id=9072671 " >MEDLINE</A>

3. Godish T. Indoor Air Pollution Control. Chelsea, Mich: Publishers;

1989:181.

4. Brunekreef B. The relationship between air lead and blood lead in

children: a critical review. Sci Total Environ. 1984;38:79-123. <A

HREF= " http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?db=m & form=6 & Dopt=r & u

id=6395339 " >MEDLINE</A>

5. US Environmental Protection Agency. US EPA Exposure Factors Handbook.

Washington, DC: US Government Printing Office; 1989:chap 3. Publication

EPA/600/8-89/043.

6. National Candle Association. Candle information. Available at: <A

HREF= " http://www.candles.org/facts.htm " >http://www.candles.org/facts.htm</A>.

Accessed May 31, 2000.

Letters Section Editors: J. Lurie, MD, PhD, Contributing Editor; Phil

B. Fontanarosa, MD, Deputy Editor.

<A HREF= " http://jama.ama-assn.org/issues/v284n2/fig_tab/jlt0712-6_ft.html " >In

dex of Figures and Tables</A>

__________________________________________________________________

** NOTICE: In accordance with Title 17 U.S.C. Section 107, this

material is distributed without profit for personal, research

and educational uses.

___________________________________________________________________

Regards -

Flanders

IAQ List Manager & Moderator

E-Mail: <A HREF= " mailto:iaq-owneronelist " >iaq-owneronelist </A>

Fax # 781-394-8288

Personal E-Mail: <A HREF= " mailto:rkfabf@... " >RKFABF@...</A>

<A HREF= " iaq " >IAQ List - Home</A>

iaq

<A HREF= " /links/iaq " >IAQ List - Links</A>

/links/iaq

<A HREF= " http://www.fiscorp.net/iaq/ " >Candles and Indoor Air Quality</A>

http://www.fiscorp.net/iaq/

<A HREF= " http://disc.server.com/Indices/41692.html " >Homeowners Soot Damage

Discussion</A>

http://disc.server.com/Indices/41692.html