Calibration 
Niton XREs are factory-calibrated, but regular checks are an essential aspect of quality control. 
Before Syracuse s inspectors begin to test a property, they take readings on standard reference 
materials (SRMs) whose lead levels are known to be within the anticipated range for lead in 
household dust. A manufacturer s standard is used for this calibration check. If any of these read¬ 
ings fail the quality control criteria, possible problems are investigated and the check is re-run 
until the instrument passes. If the instrument does not pass, it is sent back to Niton to be re-cali¬ 
brated. These same field checks need to be completed before and after each property is tested to 
ensure that the calibration has remained intact throughout the testing period. 
Laboratory Selection 
Using an accredited laboratory is an important quality control step for Syracuse. The residential 
dust samples are analyzed by a laboratory on EPA s National Lead Laboratory Accreditation 
Program (NLLAP) list for dust. Each state might have its own lead program and different regu¬ 
lations. For example, the New York State Department of Health requires all labs analyzing sam¬ 
ples from the state to be certified under its Environmental Laboratory Approval Program. For 
more information, contact the National Lead Information Center (NLIC) at 1-800-424-LEAD, 
visit <www.epa.gov/lead>, and your state and local health agencies. 
Proficiency Through EL PAT 
The Syracuse Lead Dust Project recommends that programs using XRL participate in the 
Environmental Lead Proficiency Analytical Testing (ELPAT) program. ELPAT is run by the 
American Industrial Hygiene Association and is designed to help a laboratory assess and/or 
improve its analytical performance, by providing it with test samples on a quarterly basis and 
evaluating the results. Participation in the ELPAT program is open to all laboratories, but it is 
mandatory for laboratories seeking accreditation by one of the organizations recognized under 
EPA s NLLAP program. 
XRF Usage and Radiation Exposure 
S tate regulations concerning the use of dosimetry vary; however, it is typically recommended that 
an XRF operator wear a dosimetry badge, which monitors exposure to radiation. Even though 
no radiation dosimetry is required for some isotopes, users should wear a dosimetry badge for the follow¬ 
ing reasons: 
• XRF instrument operators have a right to know the level of radiation to which they are exposed dur¬ 
ing the performance of the job. In virtually all cases, the exposure will be far below applicable expo¬ 
sure limits. 
• The cost of dosimetry is low. 
• Long-term collection of radiation exposure information can aid both the operator (employee) and the 
employer. The employee gains peace of mind and the employer benefits by having an exposure record 
that can be used in deciding possible health claims. 
• The public benefits by having exposure records available to them. 
• The need for equipment repair can be quickly identified. 
4 6 
Chapter 6 
