Air, Water and Land Pollution Chapter 1: Introduction Copyright © 2010 by DBS Contents • Introduction • Environmental Sampling • Environmental Analysis Introduction • Some examples of scientific studies… Tellus, Vol. 28, No. 6, pp. 538-551. Acidification: Finding the ‘Smoking Gun’ Have European lakes Acidified Naturally? Introduction Objectives of Study Parameters of Study Systematic steps in a monitoring program Sampling Methods Analytical Methods Data: Recording, Analysis, Presentation Information Dissemination Quality control begins (does not end) here! Body burdens of lead in ancient people uncontaminated by industrial lead (left); typical Americans (middle); people with overt clinical lead poisoning (right). Each dot represents 40 µg of lead. Source: Patterson et al., 1991; adapted from NRC, 1980. Introduction • Sampling and analysis – can’t have one without the other Introduction • Objectives of environmental sampling and analysis – Vary depending on the specific task at hand e.g. 1. Determining pollutant emissions from smoke stacks, wastewater discharge, etc. in order to comply with regulatory requirements 2. Measuring background concentrations in order to assess the degree of pollution and to identify long-term trend 3. To study the fate and transport of contaminants and to evaluate the efficiency of remediation systems Rain water mg L-1 similar Ca2+/Cl- River water Cl-/SO42- mg L-1 Sea water g l-1 Gibbs, 1970 Introduction Quality of data, and therefore the overall quality of the study depends on the sampling, analysis and interpretation… Introduction Since sampling comes first, a #*$%y sample will lead to poor data and observations… Introduction Also a huge waste of money since analysis can be pricey… Introduction • Analysis – requires reporting of analytical errors (precision, accuracy, recovery, etc.) • Must be communication between sampler and analyst to ensure preservation and storage protocols Introduction Importance of Scientifically Reliable and Legally Defensible Data • Examples of scientifically defective data: – Incorrect sampling protocol – Incorrect analytical protocol – Lack of good laboratory practice (GLP) – Falsification of results Introduction Importance of Scientifically Reliable and Legally Defensible Data • GLP Introduction Importance of Scientifically Reliable and Legally Defensible Data • • Legally defensible data is critical in industrial and governmental work Components include: – Custody or control – Documentation – Traceability (paper trail) – accuracy of standards with certificate of analysis • Find examples of falsified environmental data Introduction Sampling Error vs. Analytical Error • Errors can occur at any time throughout a study Introduction Sampling Error vs. Analytical Error • Two types of errors: – Determinate errors (systematic) – errors that can be traced to their source – Indeterminate errors (random) • Random error is dealt with by applying statistics to the data Introduction Sampling Error vs. Analytical Error • Two types of errors: – Determinate errors (systematic) – errors that can be traced to their source – Indeterminate errors (random) • Random error is dealt with by applying statistics to the data Introduction Sampling Error vs. Analytical Error • • • • General consensus is that most error comes from sampling rather than analysis Direct consequence of the heterogeneity of the environment Samples must be representative of the features of the parent material being investigated (Crumbling et al., 2001) Errors can be quantified and minimized through design and implementation of a quality program – Quality control (QC) and quality assurance (QA) – QC is a system of technical activities to control data quality – QA is a management system that ensures QC is working as intended Introduction Environmental Sampling Scope of Environmental Sampling • Steps in a sample’s life: – Sample is planned – Identification of sampling point – Collection of sample – Transfer to a laboratory – Sample is analyzed (destructive/non-destructive) – Sample expires and is discarded – Sample is represented as a data point Sampling Objective: Collect a portion of material small enough in volume to be transported and large enough for analysis while still accurately representing the material being sampled Introduction Environmental Sampling Where, When, What, How, and How Many • Choice of where (spatially) and when (temporally) to take samples should be based on sound statistics (judgmental, systematic, random, stratified, systematic, composite, etc.) • No set rules • Best sample number is the largest possible! • Quantity should not be increased at the expense of quality… Lab or Field Analysis? What are the relative merits of lab and field analyses? Lab Pros: analyses performed under optimum conditions, leading to maximum accuracy, precision will also be maximized Cons: transport, time delay in getting results, changes to sample during storage, cost to operate lab Field Pros: instantaneous results, no errors due to storage, possible to analyze in-situ, possible to use continuous monitoring Cons: conditions may not be optimum, lower precision and accuracy, Question Can you guess which of the following water quality determinations are best made in the lab or in the field? Nitrate, metals, temperature, pH, dissolved oxygen Field Lab Temperature Metals pH Nitrate DO Organics Introduction Environmental Analysis • Standard analytical methods should be used wherever possible • Regulatory agencies require very specific protocols to be followed Introduction Environmental Analysis Uniqueness of Modern Environmental Analysis • • • • • • There are numerous environmental chemicals, and the costs for analysis are high There are numerous samples that require instrument automation Sample matrices are complex, matrix interferences are variable and not predictable Chemical concentrations are usually very low, requiring increasingly more sophisticated instruments to detect ppm, ppb, ppt levels Some analyses have to be done in-situ (on site) continuously Analysts need both technical background and knowledge of regulations for regulatory compliance and enforcement Introduction Environmental Analysis Classical and Modern Analytical Monitoring Techniques • e.g. classical titration vs. automated titrator Introduction Environmental Analysis Classical and Modern Analytical Monitoring Techniques • Classical methods – include gravimetric and volumetric methods (wet chemical) • Modern methods – include spectrometric, electrometric and chromatographic techniques Introduction Environmental Analysis Classical and Modern Analytical Monitoring Techniques Introduction Environmental Analysis References • • • • • • • • Clesceri, L.S., Greenberg, A.E., and Eaton, A.D., eds. (1998) Standard Methods for the Examination of Water and Wastewater, 20th Edition. Published by American Public Health Association, American Water Works Association and Water Environment Federation. Cleaves, K.S. and Lesney, M.S. (2005) Capitalizing on Chromatography: LC and GC have been key to the central science. Enterprise of the Chemical Sciences, pp.75-82. Crumbling et al (2001) Managing uncertainty in environmental decisions. Environmental Science and Technology, Vol. 35, pp. 404A-409A. Fifield, F.W. and Haines, P.J. (2000) Environmental Analytical Chemistry, 2nd edition. Blackwell Science, Malden, MA. Filmore, D. (2005) Seeing Spectroscopy: Instrumental “eyes” give chemistry a window on the world. Enterprise of the Chemical Sciences, pp. 87-91. Gibbs (1970) referenced in Reeve, R.N. (2002) Introduction to Environmental Analysis. Wiley. Kegley, S.E. and Andrews, J. (1998) The Chemistry of Water. University Science Books. Popek, E.P. (2003) Sampling and Analysis of Environmental Chemical Pollutants: A Complete Guide. Academic Press, San Diego, CA.