Environmental Health Criteria 214

HUMAN EXPOSURE ASSESSMENT
Equipment maintenance and calibration
Internal audit and corrective action
Sample handle management
A fundamental step in the QA process is the delineation of the
study objective and a description of the study design which describes
the study population, the data to be collected and the statistical
analysis to be performed to meet the objectives. The programme
management must be described (which identifies individuals in the
programme and defines their responsibility from management, field
monitoring, sample handling, sample analysis, data reduction and
reporting). All programmes must have a QA officer who is independent
of the programme and organization and who has oversight of all QA
activities. The QA plans must define data quality objectives
(accuracy, precision, detection limit, representativeness and
completeness) and demonstrate that they are adequate to meet the study
objectives. Specific procedures for generating and validating study
data are given. An important component of any exposure study is
demonstrating the feasibility of all study procedures through a pilot
study which should be included in the QA plan. For complex field
studies where methods of procedures may require modification in the
field, it is important to clearly delineate corrective action
procedures. Standard operating procedure (SOPs), detailed protocols
for all components of the study, are appended to the QA plan. A
description of these are given in section 11.4.3.
11.4 Quality assurance programme
Important elements in assuring that the outcome and data
generated from the laboratory is accurate and reliable depends on the
QA programme implemented by the laboratory. Key elements are given in
the following.
11.4.1 Organization and personnel
It is important for the competent laboratory to establish an
organization that can function to best serve the need of the testing
facilities, regardless of the specific organization structure,
personnel include management, study directors, QA coordinator and
support staff. Properly trained personnel are crucial to the conduct
of a quality study. The training requirements and procedures should
cover professional, technical and support staff, to assure that they
have adequate knowledge and skills to carry out their duties.
11.4.2 Record-keeping and data recording
Detailed records, with dates, should be kept on the introduction
of new batches of so-called useable supplies (e.g., filters, reagents,
sample containers, plasticware, pipettes, etc). Likewise, any changes
in instrumentation or personnel have to be recorded. Afterwards, when
identifying the reasons for changed analytical performance, this kind
of thorough record-keeping is of utmost importance.
The risk of introducing errors while transcribing data into
record books or entering them into computer files is quite large.
These are so-called clerical or human errors which may involve not
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