Lead for Dummies

Occurrence of Bromine, Lead, and Zinc in Synthetic Turf Components
Philip Dickey, Staff Scientist, Washington Toxics Coalition
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Lead
Lead was found at 1952 to 1993 ppm in two measurements of the Motz 24/7 PE/nylon
turf/backing sample when X-rayed from the turf side (e.g. Figure 4e). The reading
dropped to 974 ppm when X -rayed from the backing side, indicating that the lead is
probably in the turf rather than the backing. This particular turf has a nylon fiber threaded
through the polyethylene yarn. The Motz PE turf (without the nylon) did not show any
lead.
Lead was also found at 534 and 692 ppm in duplicate tests of the ARMS ProPlay pad
when X -rayed from the backing side (spectrum not shown). When x-rayed from the
aggregate side, lead readings were 34.5, however, that because of the heterogenous character of this material, the tests are not true
replicates because the X-ray beam was seeing different parts of the sample in each. This
test does suggest, however, that most of the lead detected is in the backing material rather
than the aggregate itself.
Lead contamination is of particular concern because lead has no useful function in the
body but it harms children’s intelligence at quite low concentrations in the body. Since
1973, the action level of lead in children’s blood (the point at which exposure reduction is8
recommended) has been lowered from 40 to 10 ug/deciliter, and the argument has been
made that it should be lowered even further to 2 ug/deciliter.(5)Toxicologist Steven Gilbert
notes, “Currently, there appears to be no safe level of lead exposure for the developing
child.”(6)
 Lead is listed as a carcinogen and developmental toxicant by the State of
California.
Ideally, lead exposure would be zero, but lead is present in soils at background levels,
usually lower than 50 ppm, although ambient concentrations, especially in urban areas,
can be much higher. A reasonable level of concern can be estimated by comparing to
allowed levels of lead in soil amendments such as compost and to cleanup levels required
for hazardous waste sites. Table 3 summarizes these reference concentrations.
Table 3. Standards and Guidelines for Lead
Source Medium/location Level (ppm)
EPA Soil/children’s play areas 400
7
EPA Soil/rest of yard 1200
7
WA Soil/residential cleanup standard 250
8
EPA Biosolids (Class A/high quality) 300
9
40 CFR Part 503
Biosolids (ceiling) 850
9
EPA Compost products 150
10
From a risk perspective, if the lead is inaccessible the risk is negligible. Therefore the
presence of lead in padding or other layers below the turf may not be a concern for users
of the turf. However, a precautionary principle approach to purchasing would seek to
avoid products containing lead.
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http://www.sf-recpark.org/ftp/uploadedfiles/wcm_recpark/SPTF/rptsyntheticturftesting1007.pdf