Monitoring the Environment as an Environmental Health Professional
As an Environmental scientist we are saddled with certain responsibilities such as monitoring the quality of our environment. Environmental monitoring can be described as the systematic sampling of air, water, and soil to observe and study the environment. It involves the processes and activities that need to take place to characterize and monitor the quality of the environment. Environmental monitoring is used in the preparation of environmental impact assessments and many circumstances in which human activities carry a risk of harmful effects on the natural environment.
It also involves monitoring of the level of toxins, chemical pollutants, microbial contaminants, and other harmful substances in the environment or workplace by measuring the amount of these toxicants in the plants and animals (Man inclusive) in the environment. The data gathered provides information for evaluation, certain mitigation processes, and the actual effects of human activities on the environment.
Environmental monitoring can be conducted by researchers, government agencies, NGOs etc. It is essential in environmental impact assessment and evaluation of certain effects of harmful substances in the natural environment. Equipment used in Environmental monitoring include Thermometers, Light meters, multi-function environment meters (sound, light and humidity levels), sound level meters, humidity meters, etc. In-situ and Ex-situ measures inclusive.
DESIGNING AN ENVIRONMENTAL MONITORING SCHEME
All scientifically reliable environmental monitoring is performed in line with a published programme. The programme may include:
the overall objectives of the project,
references to the specific strategies that helps deliver the objective and
Details of specific projects or tasks within those strategies.
However the key feature of any programme is the listing of what is being monitored and how that monitoring is to take place and the time-scale over which it should all happen.
Typically, a monitoring programme will provide a table of locations, dates and sampling methods that are proposed and which, if undertaken in full, will deliver the published monitoring programme.
There are a number of commercial software packages which can assist with the implementation of the programme, monitor its progress and flag up inconsistencies or omissions but none of these can provide the key building block which is the programme itself.
PARAMETERS FOR MONITORING
Chemical
The range of chemical parameters that have the potential to affect any ecosystem is very large and in all monitoring programmes it is necessary to target a suite of parameters based on local knowledge and past practice for an initial review. The list can be expanded or reduced based on developing knowledge and the outcome of the initial surveys.
Freshwater environments have been extensively studied for many years and there is a robust understanding of the interactions between chemistry and the environment across much of the world. However, as new materials are developed and new pressures come to bear, revisions to monitoring programmes will be required. In the last 20 years acid rain, synthetic hormone analogues, halogenated hydrocarbons, greenhouse gases and many others have required changes to monitoring strategies.
Biological
In ecological monitoring, the monitoring strategy and effort is directed at the plants and animals in the environment under review and is specific to each individual study. However in more generalized environmental monitoring, many animals act as robust indicators of the quality of the environment that they are experiencing or have experienced in the recent past. One of the most familiar examples is the monitoring of numbers of Salmonid fish such as Brown trout or Salmon in river systems and lakes to detect slow trends in adverse environmental effects. The steep decline in salmonid fish populations was one of the early indications of the problem that later became known as acid rain.
In recent years much more attention has been given to a more holistic approach in which the ecosystem health is assessed and used as the monitoring tool itself. It is this approach that underpins the monitoring protocols of the Water Framework Directive in the European Union.
Microbiological
Bacteria and viruses are the most commonly monitored groups of microbiological organisms monitored and even these are only of great relevance in the aquatic environment where subsequent use as drinking water is involved or where water contact recreation such as swimming or canoeing is practiced.
Although pathogens are the primary focus of attention, the principal monitoring effort is almost always directed at much more common indicator species such as Escherichia coli supplemented by overall coliform bacteria counts. The rationale behind this monitoring strategy is that most human pathogens originate from other humans via the sewage stream. Many sewage treatment plants have no sterilization final stage and therefore discharge an effluent which, although having a clean appearance, still contains many millions of bacteria per litre, the majority of which are relatively harmless coliform bacteria. Counting the number of harmless (or less harmful) sewage bacteria allows a judgment to be made about the probability of significant numbers of pathogenic bacteria or viruses being present. Where E. coli or coliform levels exceed pre-set trigger values, more intensive monitoring including specific monitoring for pathogenic species is then initiated.
Sampling methods
There are a wide range of sampling methods which depend on the type of environment, the material being sampled and the subsequent analysis of the sample. At its simplest a sample can be filling a clean bottle with river water and submitting it for conventional chemical analysis. At the more complex end, sample data may be produced by complex electronic sensing devices taking sub-samples over fixed or variable time periods.
Grab samples
Grab samples are samples taken of a homogeneous material, usually water, in a single vessel. Filling a clean bottle with river water is a very common example. Grab samples provide a good snap-shot view of the quality of the sampled environment at the point of sampling and at the time of sampling. Without additional monitoring, the results cannot be extrapolated to other times or to other parts of the river, lake or ground-water.
Composite samples
These are individual samples taken and deposited in the same collection bottle. There are two methods that are most common to collecting composite samples. Time paced is when samples are collected at set increments of time and Flow paced samples are taken when a measured volume of water s over the sensor of a flow meter. The preferred method of sampling is by flow pacing. This gives the most representative sample. Metals, Base/Neutral/Acid Organics, BOD and TSS samples may be collected by this method.
Grab composite samples
This procedure is not commonly used but is useful for such parameters as total oil and grease released to the sewer system in a 24-hour period. Individual samples are grabbed in the field and then composited in the lab or in the field for analysis. Another variation on grab composite is the flow-proportioned grab composite. Samples are grabbed in the usual manner but the flow level is recorded at the time of sampling. After all the predetermined times of sampling are done the composite is made with portions of each grab sample according to the amount of flow at the time of sampling.
Volatile organic compounds grab samples
These samples are collected in a clean glass beaker and transferred to 40-milliliter vials, usually with HCl acid for a preservative. The cap has a flexible septum in it. There must not be any air bubbles in the vial, so the cap must not have an air space under it. The vial must be filled until the liquid crowns and the cap screwed until the septum bulges.
Discrete samples
This method is used when you want to look at the characteristics of the wastewater flow at certain times of the day, for certain parameters, such as high or low pH, or for high or low flow events. Samples are taken in individual bottles at the time of the event and each sample is analyzed. This method can also be used for flow composites if the flow rate is recorded at the time of sampling
Semi-continuous monitoring and continuous samples
There are a wide range of specialist sampling equipment available that can be programmed to take samples at fixed or variable time intervals or in response to an external trigger. For example a sampler can be programmed to start taken samples of a river at 8 minute intervals when the rainfall intensity rises above 1mm / hour. The trigger in this case may be a remote rain gauge communicating with the sampler by using cell phone or meteor burst technology. Samplers can also take individual discrete samples at each sampling occasion or bulk up samples into composite so that in the course of one day, such a sampler might produce 12 composite sample each composed of 6 sub-samples taken at 20 minute intervals. Continuous or quasi-continuous monitoring involves having an automated analytical facility close to the environment being monitored so that results can, if required, be viewed in real time.
In conclusion, Environmental monitoring is the real deal for every environmentalist, it provides a description of the environment, significant environmental impacts, mitigation actions as well as management. The environment is our concern and should be our utmost priority, let’s keep it Safe.
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