EPA LEAD INSPECTOR STUDY EXAM GUIDE QUESTIONS
AND ANSWERS SURE A+
✔✔Where does a house have the highest lead levels with respect to soil sampling? -
✔✔Dripline
✔✔What are friction, impact, and mallable surfaces? - ✔✔- Friction: rub (floors) -
Impact: smash (doors, stairs) - Mallable: edible ... protrude more than 4 in
✔✔What is the chance of lead dust from high levels of LBP? - ✔✔Twice as high
✔✔How much does water contribute to lead exposure for the average 2-year old? -
✔✔5-50%
✔✔How much lead can infants on formula receive from water? - ✔✔As much as 85%
✔✔True/False: Lead has a purpose in the body - ✔✔False; lead does nothing for the
body
✔✔Lead poisoning blood concentration - ✔✔- For children: 5 μg/dL - For adults: 50
μg/dL
✔✔How does lead travel through the body and for how long? - ✔✔- Blood (30 days) -
Soft tissues (60-90 days) - Bones (20-30 years) ... 95% of lead from an initial exposure
gets stored in bones
✔✔What body system does lead most affect? Least affect? - ✔✔- Most affects central
nervous system - Least affects lungs (point of entry)
✔✔What is the ONLY way to know if someone is lead poisoned? - ✔✔Blood lead level
✔✔True/False: You can use prophylactic chelation to maintain someone's employment -
✔✔False; chelation can only be used when blood lead reaches a certain threshold (45
μg/dL)
✔✔What do you need to transport XRF analyzers? - ✔✔- Paper documentation -
Reciprocity (agreement to allow between states)
✔✔Can you bring an XRF analyzer in a car ... what about a plane? - ✔✔- Cars: Yes ... it
must be tied down, you need a manifest, and you must keep it in line of sight- Planes:
Yes IF properly packaged
✔✔What is used to check level of radiation exposure? - ✔✔- Dosimeter - Different types
like electronic (instant reading) or body badges (after the fact) or thermoluminescent
, (TLDs ... after the fact) or ring badges - NEVER store near the XRF analyzer or
ANYTHING with radiation (e.g. computers or TV) - Dosages MUST be reported monthly
✔✔How often should you perform a leak test for XRF analyzers? - ✔✔Every 6 months
✔✔How much energy is required for cobalt-57 to excite an electron? - ✔✔128 keV
✔✔What are the units of measurement for radiation exposure? - ✔✔rad = energy per
unit of mass of material rem = rad * QF (quality factor) ... corrects for variables like the
type of tissue
✔✔Regulatory dose limits for radiation - ✔✔- Whole body: 5 rem/year - Skin/extremities:
50 rem/year - Declared pregnant worker: 0.5 rem/gestation period
✔✔What practice is in place with respect to maintaining levels of radiation exposure? -
✔✔ALARA (As Low As Reasonably Achievable) - Minimize time - Maximize distance -
Maximize shielding
✔✔True/False: An XRF analyzer can take accurate readings from any surfaces -
✔✔False; readings must be from flat surfaces
✔✔PCS - ✔✔Performance Characteristics Sheet = provides information on how to use
an XRF analyzer
✔✔Who calibrates an XRF analyzer? - ✔✔- The manufacturer calibrates the machine -
The inspector checks the calibration ... this is done the the start of a job, every 4 hours
during the job, and at the end of a job. Involves THREE checks ... values must be filled
out on a form. Positives must be between 0.8 and 1.2 mg/cm2
✔✔SRM - ✔✔- Standard Reference Material = mylar (homogenous) lead coating of
1.02 mg/cm2 - Established by NIST (National Institute for Standards and Technology)
✔✔What are the possible XRF readings? - ✔✔- Positive: at or greater than 1.0 mg/cm2
- Negative: less than 1.0 mg/cm2 - Inconclusive: must take a paint chip sample or
presume lead-based paint - Some analyzers do not give inconclusive readings because
they operate with readings around a threshold level ... check PCS to know for sure!
✔✔Substrate Correction Values - ✔✔Old way CLC (corrected lead concentrations) =
ALC (average of 3 shots of apparent lead concentration) - SEL (average of 3 shots of
substrate lead equivalent) New way - Take 3 readings on bare substrate in one spot -
Take another 3 readings on bare substrate in a new spot - Compute the correction
value = Average of the 6 readings minus the NIST SRM (1.02 mg/cm2) - Subtract this
value from the XRF readings to correct for substrate bias
AND ANSWERS SURE A+
✔✔Where does a house have the highest lead levels with respect to soil sampling? -
✔✔Dripline
✔✔What are friction, impact, and mallable surfaces? - ✔✔- Friction: rub (floors) -
Impact: smash (doors, stairs) - Mallable: edible ... protrude more than 4 in
✔✔What is the chance of lead dust from high levels of LBP? - ✔✔Twice as high
✔✔How much does water contribute to lead exposure for the average 2-year old? -
✔✔5-50%
✔✔How much lead can infants on formula receive from water? - ✔✔As much as 85%
✔✔True/False: Lead has a purpose in the body - ✔✔False; lead does nothing for the
body
✔✔Lead poisoning blood concentration - ✔✔- For children: 5 μg/dL - For adults: 50
μg/dL
✔✔How does lead travel through the body and for how long? - ✔✔- Blood (30 days) -
Soft tissues (60-90 days) - Bones (20-30 years) ... 95% of lead from an initial exposure
gets stored in bones
✔✔What body system does lead most affect? Least affect? - ✔✔- Most affects central
nervous system - Least affects lungs (point of entry)
✔✔What is the ONLY way to know if someone is lead poisoned? - ✔✔Blood lead level
✔✔True/False: You can use prophylactic chelation to maintain someone's employment -
✔✔False; chelation can only be used when blood lead reaches a certain threshold (45
μg/dL)
✔✔What do you need to transport XRF analyzers? - ✔✔- Paper documentation -
Reciprocity (agreement to allow between states)
✔✔Can you bring an XRF analyzer in a car ... what about a plane? - ✔✔- Cars: Yes ... it
must be tied down, you need a manifest, and you must keep it in line of sight- Planes:
Yes IF properly packaged
✔✔What is used to check level of radiation exposure? - ✔✔- Dosimeter - Different types
like electronic (instant reading) or body badges (after the fact) or thermoluminescent
, (TLDs ... after the fact) or ring badges - NEVER store near the XRF analyzer or
ANYTHING with radiation (e.g. computers or TV) - Dosages MUST be reported monthly
✔✔How often should you perform a leak test for XRF analyzers? - ✔✔Every 6 months
✔✔How much energy is required for cobalt-57 to excite an electron? - ✔✔128 keV
✔✔What are the units of measurement for radiation exposure? - ✔✔rad = energy per
unit of mass of material rem = rad * QF (quality factor) ... corrects for variables like the
type of tissue
✔✔Regulatory dose limits for radiation - ✔✔- Whole body: 5 rem/year - Skin/extremities:
50 rem/year - Declared pregnant worker: 0.5 rem/gestation period
✔✔What practice is in place with respect to maintaining levels of radiation exposure? -
✔✔ALARA (As Low As Reasonably Achievable) - Minimize time - Maximize distance -
Maximize shielding
✔✔True/False: An XRF analyzer can take accurate readings from any surfaces -
✔✔False; readings must be from flat surfaces
✔✔PCS - ✔✔Performance Characteristics Sheet = provides information on how to use
an XRF analyzer
✔✔Who calibrates an XRF analyzer? - ✔✔- The manufacturer calibrates the machine -
The inspector checks the calibration ... this is done the the start of a job, every 4 hours
during the job, and at the end of a job. Involves THREE checks ... values must be filled
out on a form. Positives must be between 0.8 and 1.2 mg/cm2
✔✔SRM - ✔✔- Standard Reference Material = mylar (homogenous) lead coating of
1.02 mg/cm2 - Established by NIST (National Institute for Standards and Technology)
✔✔What are the possible XRF readings? - ✔✔- Positive: at or greater than 1.0 mg/cm2
- Negative: less than 1.0 mg/cm2 - Inconclusive: must take a paint chip sample or
presume lead-based paint - Some analyzers do not give inconclusive readings because
they operate with readings around a threshold level ... check PCS to know for sure!
✔✔Substrate Correction Values - ✔✔Old way CLC (corrected lead concentrations) =
ALC (average of 3 shots of apparent lead concentration) - SEL (average of 3 shots of
substrate lead equivalent) New way - Take 3 readings on bare substrate in one spot -
Take another 3 readings on bare substrate in a new spot - Compute the correction
value = Average of the 6 readings minus the NIST SRM (1.02 mg/cm2) - Subtract this
value from the XRF readings to correct for substrate bias
