Environmental-impacts-and-health-risks

1、TRP Chapter 2.3 1Environmental impacts and health risksTRP Chapter 2.3 2Hazard and exposureMany activities have the potential to result in harm to health or the environmentHazardous wastes have properties (eg toxicity, persistence, flammability) which increase that potentialRisks : to human health t

2、o wider environment at the point of generation along the chainThose exposed to the risks include: manufacturing workers waste handlers general publicTRP Chapter 2.3 3Hazardous propertiesToxicityCorrosivityIgnitabilityReactivityEco-toxicityHealth hazardPhysical hazardEnvironmental harmUbiquitous wast

3、es - small quantities, widespread - may pose greatest risks in developing economiesChemical wastes may exhibit and may pose TRP Chapter 2.3 4Exposure routes 1Source: Jolley et al Effective and safe waste management, Interfacing Sciences and Engineering with Monitoring and Risk Analysis, 1992TRP Chap

4、ter 2.3 5Exposure routes 2 Direct physical harm Biological infection Chemical contamination Chemical alterationTRP Chapter 2.3 6Minimising risks by good management Little evidence of harm to general public health from well managed wastes Risks for industrial and waste workers reduced by proper manag

5、ement procedures and correct use of protective clothing and equipmentHealth risks may be higher : In countries or regions without modern hazardous waste management systems Around old sites with residual contamination of land or water For some groups eg childrenTRP Chapter 2.3 7Evidence of harm Epide

6、miological evidence of health effects is variable Most evidence is based on toxic effects from pure chemicals, not waste Often tests are based on animals, not humans Epidemiological evidence of causal links often weakened by confounding informationTRP Chapter 2.3 8Public concerns about hazardous was

7、te Fear of damage to health Actual (chronic or acute) health effects Nuisance from noise, dust, traffic etc Effects on quality of life Damage to natural environment Reduction in property values Lack of trust in responsible authoritiesTRP Chapter 2.3 9Public perception of risk Public concerns are inc

8、reased by high profile accidents and rare catastrophes Most concern is about involuntary risks Most people over-estimate risks There is most anxiety about long term exposure to low concentrations of compounds Actual risks can be as imprecise as perceived risksTRP Chapter 2.3 10Occupational exposureI

9、n the absence of proper management systems and without the correct protection, waste workers have been shown to suffer from elevated levels of:Respiratory illnessesSkin infectionsEye infectionsGastric problems Moving from uncontrolled waste management to a properly controlled system will greatly red

10、uce occupational risksTRP Chapter 2.3 11ScavengingScavengers: are widespread in developing economies may rely on on open dumps for their living have raised incidence of respiratory illnesses and skin and eye infections need an education programme need good personal hygiene Scavenging: should be phas

11、ed out in the long term in the short term can pose lower risks by keeping high-risk wastes out of open dumpsTRP Chapter 2.3 12Risk assessment 1 Risk assessment procedures include making estimates of: The type of harm associated with a chemical or waste substance The degree of certainty of the potent

12、ial harm The causal connection between the exposure and the potential harm The probability of the exposure and its duration The combined probabilities of harm and exposure that determine the magnitude of the risk The severity of any health or environmental impact depends on the length of exposure an

13、d the dose or amount of the harmful compoundTRP Chapter 2.3 13Risk assessment 2Conducting risk assessments: requires specialist skills is time consumingEnables comparison of relative risks from:wastes from different industrieswaste treatment and disposal methodslocations and sitesHelps set priorities for:control measuresexpenditureappropriate technologiesTRP Chapter 2.3 14Chapter 2.3 SummaryThis chapter covers