Environmental Regulationsand Possible Roles for OHs

A presentation by

Brett Ibbotson

to the

Occupational Hygiene Association of Ontario

March 2007

There are increasing opportunities in Ontario for OHs to participate in the human health risk assessments required by regulations.

In other words,

there is more (and different) work for OHs(if you want it).

In the Beginning…

• People are adept at weighing the risks and benefits of their daily activities.

• In the vast majority of cases, this is done spontaneously and on a more or less continuous basis.

The Evolution of RA

• Around 150 years ago, record keeping improves at hospitals, insurance companies, and government agencies.

• As information accumulates, it becomes possible to predict the rates of certain outcomes such a life expectancy.

• In the 1940s and 1950s, with the first attempts at harness nuclear energy, it became possible to measure tiny exposures to radioactive materials and to understand the relationship between exposure and health effects.

• By the 1960s, lessons learned by nuclear

scientists start to be applied to exposures to non-radioactive substances and chemicals.

• Some methods predict health effects based upon statistics from past exposures (epidemiology).

• Other methods predict effects based upon lab studies the dose-to-response relationship (toxicology).

OH and RA – Same but Different

At a basic level, the OH and the RA share a common objective – identify possible unwanted outcomes and take steps to reduce those to “acceptable” frequencies.

On many other levels, the two occupations are distinctly different.

• There have been OH regulations in Ontario for more than 100 years; Ontario Factories Act passed in 1884

• RA was not considered in Ontario environmental regulations until the 1980s; maximum acceptable concentrations for PCBs in soil set in 1987

• OH most often deals with healthy adult workers who are exposed for 8 h/d, 40 h/w, 50 w/y

• RA considers people of all ages, and sensitive subpopulations such as seniors. Exposures can be continuous, for years, even a lifetime. Also considers ecological receptors.

• OH addresses a wide spectrum of hazards that include machinery, chemicals, energy, noise and vibration, physical hazards, ergonomics, etc.

• RA in Ontario mostly used to address chemicals in the environment

Defining “Acceptable” Risk

• To manage risks, “acceptable” risk needs to be defined.

• How this is done appears to be an obvious point of divergence between the two disciplines.

• One cause is the human receptors each considers (healthy adults in the workplace vs the general population).

In the RA World

• This key point continues to evolve and some agencies have revised definitions occasionally.

• Common definitions in Ontario:– 1 x 10-6 for non-threshold toxicants– hazard quotient of not more than 0.2 for

threshold toxicants

Occupational limits from MOL often seem fairly liberal relative to environmental limits set by MOE.

Chemical MOL TWAEV MOE AAQC

acetone 1,200 11.8

copper 0.2 to 1 0.05

methylene chloride

175 0.044

naphthalene 52 0.023

perchloroethylene 170 0.36

All in mg/m3

• Despite challenges such as the need to define acceptable risk and what to do when “background” concentrations exceed acceptable risk levels, RA became a regular component of environmental management in Ontario during the 1990s.

RA Since 2000

In 2001, a major review of how the MOE works (the Gibbons report):

• acknowledged that RA is a primary tool for setting environmental standards

• concluded that the process could be improved by developing a new approach which it called “risk analysis” that encompasses RA, RM, and risk communication

It identified aspects of the RA approach used by the

MOE that need to be improved:

• Little attention is paid to other disciplines including sociology, economics, law, and health sciences.

• Does not deal effectively with multimedia, multichemicals, and examines sites based on artificial boundaries such as legal descriptions rather than “naturally” defined areas (like a watershed).

• Public consultation is limited to back end discussions of implementing decisions rather than up front in priority setting.

O. Reg. 153/04

• Record of Site Condition Regulation(sometimes called the Brownfields regulation)

• Presents generic standards for chemicals in soil, ground water, and sediment.

• Also gives property owners the option of using RA to recommend property-specific standards.

The RA Option in O. Reg. 153/04

• Begins by identifying the types of human and ecological receptors that could come into contact with the contaminants of concern.

• Then determines which exposure pathways could be complete.

Conceptual Site Model (CSM)

HUMAN HEALTHDIRECT CONTACT

S-1, S-2, S-3GROUNDWATER

INGESTION

INDOOR AIRECOTOXICITY

AQUATICTOXICITY

COMPONENT APPROACH

VM1Soil Vapour

Groundwater VapourContaminated Soil

AQUIFER

VM2

MAMMALS AND BIRDS

• For each potentially complete combination of receptor chemical and pathway, either measure or estimate (using mathematical models) the concentrations the receptor will encounter.

• Calculate average daily exposures and doses by combining those concentrations with receptor characteristics (i.e. body weight, inhalation and ingestion rates, etc.) and behavioral characteristics to determine frequency and duration of exposure.

• Select toxicity reference values (TRVs) for each chemical (i.e. reference doses or concentrations, inhalation unit rates, slope factors, etc.)

• Most TRVs come from published sources (MOE, Health Canada, the U.S. EPA, WHO, etc.)

• Use the TRVs to estimate potential risks posed by the estimated exposures and doses.

• Repeat the calculations in reverse, starting

with the acceptable risk levels (i.e. 1 x 10-6 or a HQ of ≤ 0.2) to calculate the corresponding maximum acceptable concentrations.

• Those maximum acceptable concentrations become the property specific standards.

• If property specific standards are exceeded, either remediate or install risk management measures.

Qualified Person in Risk Assessment

O. Reg. 153/04 requires that an RA be prepared by a team led by a qualified person in risk assessment (QPRA) who has the following qualifications:

Degree Experience in ESA or RA

Experiencein RA

Bachelors in science, engineering, or applied technology

8 years 2 years

Masters in science or engineering

7 years 2 years

Doctorate in science or engineering

5 years 2 years

The RA Team

Expected to have various “key team members”, which as a minimum, need to address the following areas:

• Human health toxicity*• Ecotoxicity*• Hydrogeology*• Soil science or chemistry• Environmental science or chemistry• Analytical chemistry• Engineering

O. Reg. 419/05

• principal air quality regulation in Ontario

• sets standards for many chemicals in outdoor air

• many of the generic standards have been set to ensure that risk levels not exceed 1 x 10-6 or HQs of 1

• Includes a schedule of dates when various categories of emitters are to comply with the standards.

• Emitters not able to meet generic standards by the prescribed dates can set “alternative standards” and embark upon a program of continuous improvement until generic standards are met.

• The Guideline for the Implementation of Air Standards in Ontario or GIASO describes the procedure.

• Like the RSC Regulation, GIASO describes

the alternative standard procedure in considerable detail.

• The assessor identifies the locations of the human receptors to be evaluated.

• Prescribed air dispersion models are used to estimate concentrations at each receptor location.

• “Risk scores” are calculated based on factors such as how frequently a standard is exceeded and weighting factors that are based on the types of adverse health effects a chemical can cause.

• Risk scores are combined to help choose control options.

• Unlike the RSC regulation, there is nothing analogous to the QP. In fact, there is no description of who can develop alternative standards.

• There is a potential role for a toxicologist or OH to work with an air dispersion modeler to establish the risk scores.

Conclusions

• Increasingly, in Ontario, environmental policies and regulations are advocating decisions based on managing human health and ecological risks.

• There are various scenarios where property owners, facility operators, and consultants can prepared human health RAs.

• There is a growing expectation that these assessments be prepared by RA teams.

Conclusions

There are increasing opportunities in Ontario for OHs to participate on the HHRAs required by regulations.

In other words, there is more (and different) work for OHs (if you want it).

Some Important Statistics

• By 2017, 50% of all the senior managers, directors, and supervisors currently in the Canadian workforce will have retired.

• For each two people who retire, there will be less than one new person entering the workforce.

• At the same time, the amount of RA and RM to be done will continue to increase.

What Could This Mean?

• Increasing pressure to work beyond 65.

• Increasing pressure for baby boomers to take on mentoring roles. Current university and college curricula pay little attention to RA. It is a skill largely learned by participating.

• With more RA work to be done, and toxicologists already in short supply, OHs will be sought out to assist with HHRAs.

The Real Conclusion?

There is more (and different) work for OHs.

It may coming looking for you even if you don’t go looking for it.