Appendix D Food Codes for NHANES - OEHHA

Scientific Review PanelSRP Draft Version 2 February,June 2012
J.4.4.2 Transfer from Air to Blood
Equation J-10 describes estimation of aggregate transfer from airborne and
associated sources that appears in the OEHHA 1997 report on the health effects
of airborne inorganic lead (OEHHA, 1997):
Slope factor = (Cbloode - Cbloodr )/(Caire – Cairr) Eq.-J-10
(Cbloode - Cbloodr ) is the difference between lead concentration in the blood of
exposed compared to reference group and (Caire – Cairr) is the difference in air
lead between exposed and reference group. This simplified model assumes that
the exposed and reference communities are similar in confounders such as age
and smoking habits and reasonably comparable in their exposure to other
sources of lead (e.g. paint).
Subsequent to OEHHA’s 1997 report, Ranft et al (2008) published results from
studies conducted on exposure to air pollutants among residents living near
industrial sources along the rivers Rhine, Ruhr and Wupper in North Rhine-
Westphalia Germany during five time-periods from 1983 to 2000. Authors
reported the distribution of ambient air lead levels for each of the five timeperiods
(Ranft et al., 2008).
During the early years (1983 – 1991), ambient air lead levels ranged from 0.100
– 0.510 µg/m 3 . Whereas, during the later years (1997 – 2000), air lead levels
were much more variable - ranging from 0.025 to 0.729 µg/m 3 . The 50 th
percentile (P 50) declined by almost a factor of 20 from years 1983 to 2000.
During the earliest years (1983 – 1991), P 50 declined by a factor of four from
0.465 to 0.100 µg/m 3 . Based on data collected from 1991 to 2000, these
investigators reported that childhood blood lead would decrease by a factor of
6.4: 95%CI (6.02 – 6.80) from the decrease in lead concentration in polluted
ambient air (m 3 /dL).
OEHHA calculated a similar slope factor from the study of 500, 55-yr-old women
living in industrial areas of the North Rhine – Westphalia, Germany from 1985 to
1990 by Wilhelm and associates (Wilhelm et al., 2007). The investigators
reported that mean blood lead levels among these women declined from 7.2 to
5.0 µg/dL. Based on ambient air levels of lead reported in Ranft et al (2008),
OEHHA estimated that blood lead levels in 55-year old women would change by
6-fold per unit of change in ambient air levels of lead (µg/dL) over a similar period
(GM, 6.2; 95% CI 6.1 – 6.4) (Ranft et al., 2008). This estimate is within the range
of slope factors reported previously by OEHHA for the general adult population
(OEHHA, 1997).
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