Hazard assessment exposure assessment dose response estimation risk characterisationecological risk assessmenttraditionally era was used investigate the effects the release particular pollutants toxic substances into environmentecological risk assessmentin era risk defined the probability that adverse effect will occur result ecosysytem exposure particular concentration the stressorriskrisk determined measuring two components the consequences effects adverse event the likelihood probability the event occurring exposure more broad application measure the relative impact potential multiple threats tomeasured and predicted impacts environmental valuesthreatsthese need identified potential riskand include point source related risks diffuse landscape-scale risksmajor risksthese include biodiversity and health aquatic and terrestrial ecosystems water quality soil quality climate changeecological risk assessment vulnerable elements the ecosystem are identified assessment endpoints are values the ecosystem protected and need identified early the analysis identification specific end points implies choices among potential target species weiner and matthews endpointsendpoints for environmental risk assessments may include numbers different species life-cycle stages for given species reproductive pattern growth pattern and matthews endpoints for ecological risk assessmentsometimes for ecological risk assessments not easy differentiate between individual and population endpoint one may have effect the other for example reduction the hatchability bird eggs individual endpoint but reduction the number hatched eggs reduces the population size
Environmental Risk Assessment (ERA)
Lecture 2
• ALLOWS OBJECTIVE COMPARISON OF RELATIVE RISK CONTRIBUTED BY EACH SPECIFIC ‘THREAT’ TO SITUATIONS IN THE ENVIRONMENT THAT NEED TO BE MANAGED
ENVIRONMENTAL RISK
END POINTS
PRIOR TO THE COMMENCEMENT OF
ENVIRONMENTAL RISK ASSESSMENT THE END
POINTS ie THE ENVIRONMENTAL VALUES THAT MUST BE PROTECTED MUST BE IDENTIFIED AND AGREED UPON BY THE STAKE HOLDERS
• INDIVIDUAL END POINT INDICATES THAT THE INTENT IS TO PROTECT INDIVIDUAL MEMBERS OF A SPECIES FROM HARM
• A POPULATION ENDPOINT ALLOWS THE
EVALUTION OF RISK IN TERMS OF HARM TO THE POPULATION OF A SPECIES AS A WHOLE FROM DECLINE BUT NOT NECESSARILY PROTECTING INDIVIDUAL MEMBERS OF THE SPECIES
RISK
ENVIRONMENTAL RISK ASSESSMENT:
• THERE ARE NO SET TOLERABLE RISK LEVELS
• THERE ARE NO SET OF ECOLOGICAL VALUES WHICH MUST BE PROTECTED THROUGH LIMITING THE DOSE OF A DAMAGING AGENT
• EXPOSURE PATHWAY
UNIQUE FEATURES OF ECOLOGICAL RISK ASSESSMENT
| • |
|---|
ECOLOGICAL RISK ASSESSMENT
RISK IS DETERMINED BY MEASURING TWO COMPONENTS
• THE CONSEQUENCES (EFFECTS) OF AN ADVERSE EVENT
THREATS
THESE NEED TO BE IDENTIFIED AS POTENTIAL RISK
THESE INCLUDE
• BIODIVERSITY AND HEALTH OF AQUATIC AND TERRESTRIAL ECOSYSTEMS
• WATER QUALITY
• SOIL QUALITY
• CLIMATE CHANGE
ENDPOINTS
ENDPOINTS FOR ENVIRONMENTAL RISK ASSESSMENTS MAY INCLUDE
• FOR EXAMPLE A REDUCTION IN THE HATCHABILITY OF BIRD EGGS IS AN INDIVIDUAL ENDPOINT BUT REDUCTION IN THE NUMBER OF HATCHED EGGS REDUCES THE POPULATION SIZE
