Industrial Hygiene Statistics I - Basics

Location – (Web PDC)

Instructions regarding how to log onto the web PDC and the conference call phone number, as well as handouts, will emailed to the registered participants at least twenty four hours prior to the web PDC.


Paul Hewett Ph.D. CIH

Course Description

This 2.5 hour webinar PDC consists of Part I of a two part introduction to Industrial Hygiene Statistics (IH Statistics). IH Statistics refers to those statistical methods and concepts that have proved useful for characterizing occupational exposure data and for IH decision making. (See the list of Prerequisites.)

Part I covers the statistical methods used to estimate the parameters of the exposure profile (i.e., distribution of exposures). Included is an introduction to the normal, z-value, and lognormal distributions; distribution parameters vs. sample statistics; goodness-of-fit testing; descriptive statistics; compliance statistics (percentiles and exceedance fractions); confidence intervals and hypothesis testing; and non-parametric statistics.

The webinar will last 2.5 hours, with an additional 30 minutes for followup questions and clarifications. Each participant will receive an email confirming participation in the PDC.

Learning Objectives

  • Ability to calculate and interpret both descriptive and compliance statistics.
  • Ability to calculate and interpret confidence intervals for the most commonly used compliance statistics.
  • Ability to use both subjective and objective goodness-of-fit procedures to validate the use of the lognormal distribution model.
  • Appreciation of the relationships between exposure data, sample statistics, and IH decision making.
  • Awareness of the major issues, pitfalls, and problems associated with the analysis and interpretation of occupational exposure data.


  • Familiarity with the AIHA Exposure Assessment and Management Model (see the AIHA monograph “A Strategy for Assessing and Managing Occupational Exposures”, 3rd Edition (2006)
  • Working knowledge of the IHDataAnalyst (Professional or Student Edition).
  • Recommended reading prior to the WebPDC:
    • Hewett, P. (2007): Technical Report 07-02 – Industrial Hygiene Exposure Assessment – Data Collection and Management. Exposure Assessment Solutions, Inc.
    • Hewett, P. (2007): Technical Report 07-03 – Industrial Hygiene Exposure Assessment – Data Analysis and Interpretation. Exposure Assessment Solutions, Inc

Presentation List

  • AIHA Exposure Control Model
  • Baseline Survey Simulator Workshop
  • Introduction to the IH Data Analyst – Lite Edition
  • Distributions
  • Descriptive and Compliance Statistics
  • Goodness-of-fit
  • Order Statistics
  • Exposure Assessment Issues and Pitfalls


$250 per participant

Cancellation Policy

A credit for an upcoming web PDC or a refund will be given for any cancellation made at least one business day prior to the day of the class. For example, if the web PDC is presented on a Saturday, the cancellation must be made by 6PM (1800) US Eastern time on the previous Thursday in order to qualify for a credit or refund. All refunds will be minus a $50 fee to recover credit card fees and administrative costs. No refunds or credits will be given if the notice of cancellation is not received within one business day of the web PDC.

Exposure Assessment Solutions, Inc. reserves the right to cancel the PDC at any time, in which case a full refund or credit will be given to each participant.

Read these notes before you sign up:

NOTE: The registration and participation policy for each Web PDC is the same as for a fixed location or on-site PDC. Registration is per participant, not per viewing site. Each participant must register.  Only those registered should view and participant in this web PDC.

NOTE: The email address submitted at the time of payment will be used for all email communications and for logging onto the web PDC.

NOTE: This web PDC will presented using GoToMeeting. GoToMeeting must be installed on your computer. To install (usually takes less than two minutes), click on the GoToMeeting link above, scroll to the bottom of the page, and click on the link “Download GoToMeeting (for customers)”. If you do not have adminstrative privileges for your computer have your IT person install the GoToMeeting software well in advance of the web PDC.

NOTE: The conference call number will not be toll free. You will be responsible for any long distance phone charges if you do not have an unlimited long distance account. However, you may also connect using your computer speakers and microphone or headset (VoIP).

NOTE: See the “Prerequisites” below for software and freeware that will be helpful when taking this web PDC. To download and install the program(s) you must first be a registered member of