1 lb chemical 454,000,000 μg
1 yr
93,879 μg chemical
×
×
=
yr
lb
4,836 m
m
3
m
3
Subsequently, this value was multiplied by the IUR (μg/m 3 ) −1 . As noted with the
ingestion carcinogenicity TF, we then multiplied this result by 1 million people to
obtain the estimated number of individuals who could equally share/inhale (number
of doses) a pound of the chemical and still result in an acceptable level of cancers:
62
Toxic Chemicals
chemicals will be overwhelming, and ultimately nothing will be done to reach the
next step of reducing overall toxicity.
INGESTION CARCINOGENIC TOXICITY FACTOR DEVELOPMENT
For the ingestion carcinogenicity TF, we took a pound of a chemical per year, converted it to milligrams per day using standard unit conversion factors, and divided
by a typical average body weight (70 kg) and 365 days per year:
1 lb chemical 454,000 mg
1 yr
1
18 mg chemical
×
×
×
=
yr
lb
365 days 7 70 kg
kg-day
Subsequently, this value was multiplied by the SFO (mg/kg-day) −1 to yield the
portion of the population that could develop excess cancers due to exposure of 1 lb
of chemical released:
18 mg chemical SFO (kg-day)
w
kg-day
mg
However, this is not an acceptable risk. While no cancer is desirable, there is a
threshold of cancer risk that is generally acceptable, and according to the USEPA,
this is usually from 1 excess cancer case per 100,000 people to 1 excess cancer case
per million people. For this analysis, we factored in 1 excess cancer risk per million
people and hence multiplied the result by 1 million to obtain the estimated number
of individuals who could share/ingest (number of doses) a pound of the chemical
released and still result in an “acceptable” level of cancers:
18 mg c chemical SFO (kg-day)
Ingestion Carcinogenic TF (doses/lb) =
×
× 10
6 people
kg-day
mg
INHALATION CARCINOGENIC TOXICITY FACTOR DEVELOPMENT
According to the USEPA, the adult male inhalation rate is 15.2 m 3 /day, and the adult
female inhalation rate is 11.3 m 3 /day. Hence, the average inhalation rate for an adult
is 13.25 m 3 /day, or 4,836 m 3 /yr, using the standard conversion factor of 365 days
per year. For the inhalation carcinogenicity TF, we took a pound of a chemical per
year and converted it to micrograms per cubic meters using standard unit conversion
factors and the average annual inhalation of air (4,836 m 3 /yr):
1 yr
93,879 μg chemical
×
×
=
yr
lb
4,836 m
m
3
m
3
Subsequently, this value was multiplied by the IUR (μg/m 3 ) −1 . As noted with the
ingestion carcinogenicity TF, we then multiplied this result by 1 million people to
obtain the estimated number of individuals who could equally share/inhale (number
of doses) a pound of the chemical and still result in an acceptable level of cancers:
62
Toxic Chemicals
chemicals will be overwhelming, and ultimately nothing will be done to reach the
next step of reducing overall toxicity.
INGESTION CARCINOGENIC TOXICITY FACTOR DEVELOPMENT
For the ingestion carcinogenicity TF, we took a pound of a chemical per year, converted it to milligrams per day using standard unit conversion factors, and divided
by a typical average body weight (70 kg) and 365 days per year:
1 lb chemical 454,000 mg
1 yr
1
18 mg chemical
×
×
×
=
yr
lb
365 days 7 70 kg
kg-day
Subsequently, this value was multiplied by the SFO (mg/kg-day) −1 to yield the
portion of the population that could develop excess cancers due to exposure of 1 lb
of chemical released:
18 mg chemical SFO (kg-day)
w
kg-day
mg
However, this is not an acceptable risk. While no cancer is desirable, there is a
threshold of cancer risk that is generally acceptable, and according to the USEPA,
this is usually from 1 excess cancer case per 100,000 people to 1 excess cancer case
per million people. For this analysis, we factored in 1 excess cancer risk per million
people and hence multiplied the result by 1 million to obtain the estimated number
of individuals who could share/ingest (number of doses) a pound of the chemical
released and still result in an “acceptable” level of cancers:
18 mg c chemical SFO (kg-day)
Ingestion Carcinogenic TF (doses/lb) =
×
× 10
6 people
kg-day
mg
INHALATION CARCINOGENIC TOXICITY FACTOR DEVELOPMENT
According to the USEPA, the adult male inhalation rate is 15.2 m 3 /day, and the adult
female inhalation rate is 11.3 m 3 /day. Hence, the average inhalation rate for an adult
is 13.25 m 3 /day, or 4,836 m 3 /yr, using the standard conversion factor of 365 days
per year. For the inhalation carcinogenicity TF, we took a pound of a chemical per
year and converted it to micrograms per cubic meters using standard unit conversion
factors and the average annual inhalation of air (4,836 m 3 /yr):