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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.
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste .
Space pollution — Space debris • Interplanetary contamination Resource depletion — Exploitation of natural resources • Overdrafting (groundwater) • Overexploitation Consumerism — Consumer capitalism • Planned obsolescence • Over-consumption
It was the first U.S. nuclear field exercise conducted on land; troops shown are 6 mi (9.7 km) from the blast. See also: Nuclear and radiation accidents , List of civilian nuclear accidents , List of military nuclear accidents , and List of civilian radiation accidents
Overgrazing by livestock can lead to land degradation. Land degradation is a process where land becomes less healthy and productive due to a combination of human activities or natural conditions. The causes for land degradation are numerous and complex. [1] Human activities are often the main cause, such as unsustainable land management practices.
The Hong Kong Examinations and Assessment Authority (HKEAA) has moved from norm-referenced to standards-referenced assessment, including the incorporation of a substantial school-based summative oral assessment component(SBA) into the compulsory English language subject in the Hong Kong Certificate of Education Examination (HKCEE), a high-stakes examination for all Form 4–5 students (Davison ...
[27]: 2321 For example, the decline of sea ice in the Arctic has been accelerating during the early twenty‐first century, with a decline rate of 4.7% per decade (it has declined over 50% since the first satellite records). [28] [29] [30] One well known example of a species affected is the polar bear, whose habitat in the Arctic is threatened ...
Sources of water pollution are either point sources or non-point sources. [156] Point sources have one identifiable cause, such as a storm drain, a wastewater treatment plant, or an oil spill. Non-point sources are more diffuse. An example is agricultural runoff. [157] Pollution is the result of the cumulative effect over time.