Environmental Health Risk Assessment (Issue identification ( What are the…
Environmental Health Risk Assessment
Definition: the process of estimating the potential impact of a chemical, biological, physical, psychosocial hazard on a specified population at a specified time for a specified time frame.
Hazard = an agent that has the potential to adversely affect human health. e.g. chemical, biological, radiation, climate/climate change.
What is the difference between a HIA and EHRA?
HIA is an assessment of the likely health impacts of a program, policy or project - includes BOTH health benefits AND harms
HIA tends to be undertaken in early phases of project planning to predict and facilitate avoidance of potential negative impacts on health.
The precautionary principle: Where there are threats to serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degration."
What are the true drivers for the issue that is being assessed? What are the stakeholders worried about?! Is a RA appropriate
Are intervention options available to manage the outcomes of the EHRA?
Have transport mechanisms been adequately assessed?
Are there factors that could affect persistence of the hazard?
What are the issues/chemicals of concern and
Hazard assessment: collection and analysis of adequate data
What are the chemicals of potential concern?
Are the health harms immediate or delayed?
Is there a critical window of exposure? (e.g. fetal)
Look to human or animal toxicity studies
Have the genotoxic and/or carcinogenic potential of the identified hazards been addressed?
Data source: International Agency for Toxic Substances and Disease Registry (ATSDR), International Agency for Research on Cancer (IARC), ToxNet, EnHealth
Is dose-response data available and is it scaled to humans (from animal)
Has the potency been determined for acute and chronic dosing
Does a threshold or non-threshold model apply?
Linear or non-linear
NOAEL and LOAEL
What is a hazard? An agent that has capacity to cause harm/adverse health event.
What is the timing, duration, frequency and consistency of exposure?
Are exposures continuous, episodic or intermittent
Have all exposure routes been considered?
inhalation, ingestion, transdermal, aerosols
Often involves calling upon modelled data
This is usually when samples taken
Develop a conceptual site model
Are exposures intergenerational or cumulative?
Potential dose, applied dose, absorbed dose, target organ dose
Are there individual host characteristics that need to be considered? (age, sex, body weight, medical status, immune status, nutritional status, reproductive status)
Are there population charactersitics that need to be considered (herd immunity, social behaviours, social mobility)
Quantify the risk as liklihood and severity, quantitative or qualitative with statement of uncertainty. Is there an acceptable daily intake (ADI)?
Liklihood to materialise by impact (risk matrix)
RA informs risk management (remove or mitigate or accept (monitor)). Control measures at the level of the person, pathway and source
risk communication (Sandman)
expert risk = hazard x probability
public risk = hazard + outrage