Monitoring Chemicals in the Environment

Chia sẻ: Nguyễn Văn Quân | Ngày: | Loại File: PDF | Số trang:10

Thêm vào BST

Báo xấu

65
lượt xem 6
download

Download Vui lòng tải xuống để xem tài liệu đầy đủ

Understand the importance of tools such as quality assurance project plans to effective monitoring of environmental chemicals. • Describe the elements of a quality assurance project plan. • Describe the elements in the development of data quality objectives. • Define quality assurance and quality control.

Chủ đề:

Bình luận(0) Đăng nhập để gửi bình luận!

Lưu

Nội dung Text: Monitoring Chemicals in the Environment

Principles of Environmental Toxicology Learning Objectives • Understand the importance of tools such as quality assurance project plans to effective monitoring of environmental chemicals. Monitoring Chemicals • Describe the elements of a quality assurance in the Environment project plan. • Describe the elements in the development of data Principles of Environmental Toxicology quality objectives. Instructor: Gregory Möller, Ph.D. • Define quality assurance University of Idaho and quality control. 2 Principles of Environmental Toxicology Principles of Environmental Toxicology Learning Objectives Why Monitor? • Explore the arguments of chemical vs. biological • Public health and safety. monitoring of chemical in the environment. – Food quality, water quality, air quality. • Explore the indicator species concept. – Minimize risk. • Understand the critical • Environmental quality. elements of a quality-based – Ecological sustainability. sampling program. – Minimize risk. • Use the NPDES program as • Feedback on anthropogenic change. case study to understand a • Feedback on potential for exposure. basis and approach to • Baseline development. environmental monitoring. • Remediation/reclamation success. 3 4 Principles of Environmental Toxicology Principles of Environmental Toxicology Example Monitoring Programs Monitoring Approach • Regulatory driven. • Safe Drinking Water Act. • Hypothesis driven. • Food Quality Protection Act. • Incident driven. • Clean Water Act. • All require development of defendable data. • Reconnaissance monitoring by state and Federal agencies. • QA/QC = confidence in final result. • Environmental research investigations. • Forensic studies. 5 6 1
Principles of Environmental Toxicology Principles of Environmental Toxicology Quality Assurance Project Plan Project • Single or multiple data collection activities that are • An orderly assemblage of detailed procedures related through the same planning sequence. designed to produce data of sufficient quality to meet the data quality objectives for a specific data collection activity. 7 8 Principles of Environmental Toxicology Principles of Environmental Toxicology QA Project Plan (QAPP) QAPP Elements • Planning tool for an environmental data operation. • Project management. – History and objectives, roles/responsibilities, goal • Documents how environmental data operations are definition. planned, implemented, and assessed with respect to • Measurement/data acquisition. quality during the life cycle of a project, program or task. – Measurement system design and implementation, methods, QC. • Defines how specific QA • Assessment/oversight. and QC activities will be – Ensure QAPP was implemented. applied. • Data validation and usability. – QA activities after data collection; data conformance to criteria. 9 10 Principles of Environmental Toxicology Principles of Environmental Toxicology Data Quality Objectives DQO Elements • A strategic planning tool • Concisely defining the problem. for an environmental study. • Identifying the decision to be made. – Based on the scientific method. • Identifying the key elements to that decision. – Identifies and defines the type, quality and quantity • Defining the boundaries of the study. of data needed to satisfy particular use. • Developing the decision rule. • Specifying tolerable limits on errors. • Selecting an efficient data collection design. EPA 11 12 2
Principles of Environmental Toxicology Principles of Environmental Toxicology Quality Assurance Quality Control • An integrated system of management activities • The overall system of technical activities that involving implementation, assessment, reporting, measures the attributes and performance of a and quality improvement to ensure that a process, process, item or service, against defined standards item or service, is of the type and to verify the that they meet the stated requirements quality needed and expected established by the customer or user. by the client or user. – Operational techniques and activities that are used to fulfill requirements for quality. 13 14 Principles of Environmental Toxicology Principles of Environmental Toxicology Chemical or Biological Monitoring? “Use Chemicals” Argument • Pros • The basis of much, largely biased, debate. Jones – Precision of measurements. • Pollution is a biological phenomenon and cannot be • Cons described without reference to organisms (which – Link to biological phenomena often not available or are variable). clear. • Pollution is usually measured – What part of the system/organism is measured? in chemical terms – Localization difficult unless (BOD, concentrations, etc.) pollution is continuous or but must be related to sampling very extensive. any possible biological effect. – Sampling suffers major problems of temporal and spatial variations. Jones 15 16 Principles of Environmental Toxicology Principles of Environmental Toxicology Temporal Sampling Problems “Use Organisms” Argument • Pros – Relevance is obvious but which organisms (in the light of previous discussion)? Discharge Concentration – Being present all time (SENTINEL spp) allows detection of sporadic events. – Biological systems (individuals, populations and communities) are “damped” and integrative over time. – Localization possible by following gradients. Time 17 Jones 18 Jones 3
Principles of Environmental Toxicology Principles of Environmental Toxicology “Use Organisms” Argument Realistic Ideal is Combination • Cons • Use biology to detect a problem through biological – Spatial variability still significant. effect and then use chemistry to identify possible/probable causes – Variability of organisms can be great, both within a species and between taxa. • Requires adequate baseline data (i.e.. pre-pollution levels) – Lack of specificity of biological responses. • Indicate stress only, not source of stress. • Sub-lethal effects may be difficult to identify. • Cause and effect can never be proven categorically - only correlation and probability. Jones Jones 19 20 Principles of Environmental Toxicology Principles of Environmental Toxicology The Indicator Concept Indicator Absence • Originated as Indicator Species concept. • The absence of a species does not necessarily mean that critical environmental parameters are not – A species or species assemblage that has present. particular requirements with regard to a known set of physical or chemical variables. • Absence may be due to other factors. – Changes in presence/absence, – Geographical barriers. numbers, morphology, – Competitive exclusion by physiology or behavior of ecological analogue. that species indicate that – Life-cycle events the given physical or (predation, parasitism, etc). chemical variables are outside its preferred limits. Jones Jones 21 22 Principles of Environmental Toxicology Principles of Environmental Toxicology Ideal Indicator Requirements Sentinel Study • Taxonomic soundness and easy recognition. • Sentinel species are used for studies of Bioaccumulation (body burdens) • Cosmopolitan distribution. – e.g. the Mussel Watch program. • Numerical abundance. • The concept of Indicator Communities offers a more • Low genetic and ecological variability. valid approach? • Large body size. – A good example is that • Limited mobility and long of the “sewage community” life-history. found downstream of • Autecology well-known. organic inputs to lotic • Laboratory tolerant. systems. Jones Jones 23 24 4
Principles of Environmental Toxicology Principles of Environmental Toxicology Biological Variability Sampling Program • Biological variability need not obscure trends …but • Are samples, and therefore the data developed care is needed in the use of statistical comparison from them, indicators of the target of monitoring? techniques. • How is the sampling and analysis process – Sometimes the obvious can be statistically controlled to determine (minimize) constant or Jones difficult to prove. proportional error (bias). • Will all have confidence Trend? in the final result? • What are the limits of performance? SD – e.g., Scientific capability, cost. 25 26 Principles of Environmental Toxicology Principles of Environmental Toxicology Sample Types Field Duplicates • Field duplicates. • Independent samples which are collected as close • Blank samples. as possible to the same point in space and time. • Laboratory control sample. – Two separate samples taken from the same source, stored in separate containers, and • Split samples. analyzed independently. • Matrix control samples. – Useful in documenting the precision of sampling process. EPA 27 28 Principles of Environmental Toxicology Principles of Environmental Toxicology Blank Samples Laboratory Control Sample • Trip blank: sample of analyte-free media taken from • A known matrix spiked with EPA the laboratory to the sampling site and returned to compound(s) representative of the target analytes. the laboratory unopened. • Used to document laboratory performance. – Used to document contamination attributable to shipping and field handling procedures. • Laboratory blank: sample of analyte free media prepared as a negative control for the laboratory analysis of a batch of samples. – Lab contamination control. EPA 29 30 5
Principles of Environmental Toxicology Principles of Environmental Toxicology Split Samples Matrix Control • Aliquots of sample taken from the same container • Matrix: component or substrate and analyzed independently. (e.g., surface water, drinking water) which contains the analyte of interest. • In cases where aliquots of samples are impossible to obtain, field duplicate samples should be taken for • Matrix duplicate: intra-laboratory split sample which the matrix duplicate analysis. is used to document precision of a method in a given sample matrix. • Usually taken after mixing or compositing and are • Matrix spike: aliquot of sample spiked with a known used to document intra- concentration of target analyte(s). or inter-laboratory precision. – Occurs prior to sample preparation and analysis. – Used to document the bias of a method in a given sample matrix. EPA EPA 31 32 Principles of Environmental Toxicology Principles of Environmental Toxicology Method Detection Limit (MDL) Limits of Quantitation • The minimum concentration of a substance that • “Quantitative interpretation, decision-making can be measured and reported with 99% and regulatory actions should be limited to data at or above the limit of quantitation” (ACS). confidence that the analyte concentration is greater • "Analytical chemists must always emphasize to the public than zero. EPA that the single most important characteristic of any result obtained from one or more analytical measurements is an Determined from adequate statement of its uncertainty level.” analysis of a sample – “Lawyers usually attempt to dispense with uncertainty and in a given matrix try to obtain unequivocal statements; therefore, an type containing uncertainty interval must be clearly defined in cases involving litigation and/or enforcement proceedings. the analyte. Otherwise, a value of 1.001 without a specified uncertainty, for example, may be viewed as legally exceeding a permissible level of 1." 33 34 ACS Principles of Environmental Toxicology Principles of Environmental Toxicology NPDES Program Important Principles EPA • The discharge of pollutants to navigable • National Pollutant Discharge Elimination System. waters is not a right. • History. • A discharge permit is required to use public – 1965, legislation required states to have water quality standards by 1967. resources for waste disposal and limits the amount of pollutants that may be discharged. • Only 50% of states complied by 1971. – 1970, Refuse Act and Permit Program (RAPP). • Wastewater must be treated with the best treatment • 1971, struck down via NEPA (1969) EIS concern. technology economically achievable - regardless of – 1972, permit concept survives in federal Water the condition of the receiving water. Pollution Control Act amendments (conventionals) • Effluent limits must be based on treatment – 1977, Clean Water Act technology performance. amendments (toxics). – More stringent limits may be imposed if technology based – 1987, Water Quality Act limits do not prevent violations of water quality standards 35 EPA (effluent control). 36 in the receiving water. 6
Principles of Environmental Toxicology Principles of Environmental Toxicology NPDES Scope NPDES Program Areas • Municipal. • All facilities which discharge pollutants from any – Municipal effluent discharge. point source into the waters of the US are required to obtain a NPDES permit. – Indirect industrial/commercial discharges. EPA – Municipal sludge use and disposal. – Combined sewer overflow (CSO) discharge. – Storm water discharge. • Industrial. – Process water discharges. – Non-process water discharges. – Storm water discharges. EPA 37 38 Principles of Environmental Toxicology Principles of Environmental Toxicology Pollutants Point Source • Conventional. • Agricultural, domestic and industrial. – BOD5 (5-day biological oxygen demand), TSS – Non-point agricultural operations exempt. (total suspended solids), fecal coliform, pH, oil • Publicly owned treatment works (POTW). and grease. – Indirect • Toxic. • Industry, domestic → POTW → discharge. – 126 priority pollutants – Direct listed in 40 CFR §401.15 • Industry → discharge. • Non-conventional. – NH3, N, P, COD (chemical oxygen demand), WET (whole effluent toxicity). EPA EPA 39 40 Principles of Environmental Toxicology Principles of Environmental Toxicology Waters of the United States NPDES Permit Components • Navigable waters. • Cover page. EPA EPA • Tributaries of navigable waters. – Name, location, authorization, specific discharge. • Interstate waters. • Effluent limitations. • Interstate lakes, rivers and streams. – Based on applicable technology and water quality standards. – Used by interstate travelers for recreation and other purposes. • Monitoring and reporting reqs. – Used as a source of fish or shell fish sold in – Characterization, compliance. interstate commerce. • Special conditions. – Utilized for industrial purposes by industries – e.g. BMPs, add’l surveys. engages in interstate commerce. • Standard conditions. • Interpreted: wetlands and ephemeral streams. – Administrative requirements. 41 42 7
Principles of Environmental Toxicology Principles of Environmental Toxicology NPDES Effluent Limitations Water Quality Criteria • Technology-based effluent limits. • Typically have 3 components. EPA – ELGs, effluent limitation guidelines – Magnitude. • Process/industry based. • Concentration of pollutant. • BAT, best available control technology. – Duration. • BPT, best practical control technology. • Averaging period of time for concentration. – Frequency. – BPJ, best professional judgment (case by case). • How often criteria can be exceeded. • Water quality-based effluent limits, WQBEL. • Narrative – Site specific evaluation of a discharge and its – “Free from toxics at toxic levels” effect on receiving water; use water quality stds. • Numerical • Use classifications. – 2 μg Cd/L or • Numeric/narrative water quality criteria. • Anti-degradation policy. e (0.7852[ln(hardness)]-3.490) EPA 43 44 Principles of Environmental Toxicology Principles of Environmental Toxicology Future Standards Water Quality Determinations • Biological criteria. • Chemical Specific Approach. – Reference biological integrity; communities. • Whole Effluent Toxicity. • Sediment criteria. • Bioassessments. – Contaminants deposited over time. • Phenanthrene, fluoranthrene, dieldrin, acenaphthene, endrin. • Wildlife criteria. – Protection of mammals/birds from adverse effects from consumption of contaminated water/food. 45 EPA 46 Principles of Environmental Toxicology Principles of Environmental Toxicology Chemical Specific Approach Chemical Specific Approach • Capabilities. • Limitations. – Human health protection. – Does not considers all toxics present. – Complete toxicology. – Bioavailability not measured. – Straightforward treatability. – Interactions of mixtures (e.g. additivity) not measured. – Fate understood. – Complete testing can be – Less expensive testing. expensive. – Prevents impacts. – Direct biological impairment not measured. EPA EPA 47 48 8
Principles of Environmental Toxicology Principles of Environmental Toxicology Whole Effluent Toxicity (WET) WET • Acute (e.g. 48 hrs). • Limitations. • Chronic (e.g. 7 days) – No direct human health protection. • Capabilities. – Incomplete toxicology (few species may be tested). – Aggregate toxicity. – No direct treatment. – Unknown toxicants addressed. – No persistency or sediment – Bioavailability. coverage. – Accurate toxicology. – Conditions in ambient may – Prevents impacts. be different. – Incomplete knowledge of causative toxicant. EPA EPA 49 50 Principles of Environmental Toxicology Principles of Environmental Toxicology Bioassessments Bioassessments • Capabilities. • Limitations. – Measures actual receiving – Critical flow effects not always assessed. water effects. – Difficult to interpret impacts. – Historical trend analysis. – Cause of impact not identified. – Assesses quality above – No differentiation of sources. standards. – Impact has already occurred. – Total effect of all sources, – No direct human health including unknown sources. – protection. EPA 52 EPA 51 Principles of Environmental Toxicology Principles of Environmental Toxicology Whole Effluent Toxicity Acute to Chronic Ratio (ACR) • Toxic unit (TU), the inverse of the sample fraction, is • Compares TUa to TUc. the preferred toxicity representation. – Conversion/comparison factor. – Ex. If a chronic test result is a NOEC of 25% – Determination of most important in discharge. effluent, the result can be expressed as 100/25 or • ACR = LC50 / NOEC = (100/TUa)/(100/TUc) 4.0 chronic toxic units (4.0 TUc). = TUc / TUa – Ex. If an acute test result is • Ex. Given: LC50 = 28%, NOEC = 10% an LC50 of 60%, that result ACR = LC50 / NOEC = 28% / 10% = 2.8 can also be expressed as • Ex. TUc = 10.0, TUa = 3.6 100/60 or 1.7 acute toxic ACR = TUc / TUa = 10.0 / 3.6 = 2.8 units (TUa). • Recommended default ACR = 10. EPA EPA 53 54 9
Principles of Environmental Toxicology Principles of Environmental Toxicology Mass Balance Equation Example • Qs = 1.2 cfs QdCd + QsCs = QrCr EPA EPA • Qd = 0.31 cfs • Cs = 0.8 mg/L • Qd = waste discharge flow in million gallons per day • Cd = 2.0 mg/L (mgd) or cubic feet per second (cfs). • Water quality criterion = 1.0 mg/L • Cd = discharge pollutant concentration (mg/L). • Cr = (QdCd + QsCs) / Qr • Qs = bkgd stream flow (mgd, cfs). • Cr = [(0.31 cfs)(2.0 mg/L) + (1.2 cfs)(0.8 mg/L)] • Cs = bkgd in-stream pollutant conc. (mg/L). (1.2 cfs) + (0.31 cfs) = 1.05 mg/L • Qr = resultant in-stream flow after discharge. • Since the downstream concentration • Cr = resultant in-stream pollutant conc. after mixing. exceeds the water quality criterion, there is a reasonable potential for water quality standards to be exceeded. 55 56 Principles of Environmental Toxicology Example 2 Cr = (QdCd + QsCs) / Qr EPA • Cs = 0 T U • Qs = 23.6 cfs (acute); 70.9 cfs (chronic). • Qd = 7.06 cfs • Cd = TUa = 2.49; TUc = 6.25 • Acute criterion: 0.3 TUa; Chronic criterion: = 1.0 TUc • Cr = [(2.49)(7.06) + (0)(23.6)] / (7.06 + 23.6) = 0.57 TUa • Cr = [(6.25)(7.06) + (0)(70.9)] / (7.06 + 70.9) = 0.57 TUc • Since downstream concentration, Cr exceeds the water quality criterion for acute toxicity, there is reasonable potential for water quality standards to be exceeded. 57 10