(VCCEP) Tier 1 Pilot Submission for BENZENE - Tera

Benzene VCCEP Submission
March 2006
Table 7.28: Average Daily Doses of Benzene to Nursing
Infant of Occupationally Exposed and Urban Mothers
Scenario Average Daily Dose
(mg/kg-day)
Urban, typical 2.3E-06
Urban, high-end 1.6E-05
Occupational, typical 1.9E-04
Occupational, high-end 6.8E-04
The intake of benzene via ingestion of human milk by a nursing infant of an occupationally
exposed mother ranges from 0.9 to 6 times that received via ingestion of food and tap water.
For infants of non-occupationally exposed mothers, the benzene exposure from human milk is
0.02 to 0.07 times that received via ingestion of food and tap water. Thus, human milk ingestion
may be a significant dietary source of benzene for infants of occupationally exposed mothers.
The human milk modeling results for occupationally exposed mothers are likely to be
conservative for benzene since many employers apply administrative and management controls
that remove nursing mothers from benzene exposed jobs.
7.2.1.10 Summary of Ambient Background Benzene Exposures
Of the ambient background sources described in Section 7.2.1, inhalation of indoor air is the
predominant pathway of exposure for children and prospective parents (See Figure 7.3). For
nursing infants of occupationally exposed mothers, the predominant pathway of exposure from
ambient sources is still inhalation, but ingestion of human milk accounts for a larger portion of
background exposure (i.e., 22% vs. 5% for occupationally exposed and urban typical mothers,
respectively) (See Figure 7.4). Section 7.5 provides further discussion of estimated benzene
intake from exposure to various sources.
Figure 7.3. Predominant Pathways of Benzene Exposure for
Children and Prospective Parents from Ambient Sources
Ingestion
4%
Dermal
0%
Inhalation
96%
126
Inhalation
Ingestion
Dermal