Thursday 30 July 2015

Refining Topic Through Research

I have decided to further explore just two avenues of the over-arching topic I have chosen as these two ideas are the ones that inspire and interest me the most.


Water Pollution

"1. Promoting water efficiency strategies to help decrease the amount of water wasted;
2. Protecting our water from pollution by defending the Clean Water Act and advocating for solutions
    like green infrastructure;
3. Helping prepare cities, counties and states for water-related challenges they will face as a result of 
    climate change; and
4. Ensuring that waterways have enough water to support vibrant aquatic ecosystems.

Dirty water is the world's biggest health risk, and continues to threaten both quality of life and public health. When water from rain and melting snow runs off roofs and roads into rivers, it picks up toxic chemicals, dirt, trash and disease-carrying organisms along the way. Many water resources also lack basic protections, making them vulnerable to pollution from factory farms, industrial plants, and activities like fracking. This can lead to drinking water contamination, habitat degradation and beach closures."



"As New Zealand tries to squeeze maximum value out of its natural resources, conflicts over water are coming to a boil. We’re fast approaching water resource limits in some parts of the country, and pollution issues are threatening our clean, green brand."



"Water pollution occurs when a body of water is adversely affected due to the addition of large amounts of materials to the water. The sources of water pollution are categorized as being a point source or a non-source point of pollution. Point sources of pollution occur when the polluting substance is emitted directly into the waterway. A pipe spewing toxic chemicals directly into a river is an example. A non-point source occurs when there is runoff of pollutants into a waterway, for instance when fertilizer from a field is carried into a stream by surface runoff.

Types of Water Pollution:
  • Toxic Substance -- A toxic substance is a chemical pollutant that is not a naturally occurring substance in aquatic ecosystems. The greatest contributors to toxic pollution are herbicides, pesticides and industrial compounds. 
  • Organic Substance -- Organic pollution occurs when an excess of organic matter, such as manure or sewage, enters the water. When organic matter increases in a pond, the number of decomposers will increase. These decomposers grow rapidly and use a great deal of oxygen during their growth. This leads to a depletion of oxygen as the decomposition process occurs. A lack of oxygen can kill aquatic organisms. As the aquatic organisms die, they are broken down by decomposers which leads to further depletion of the oxygen levels. A type of organic pollution can occur when inorganic pollutants such as nitrogen and phosphates accumulate in aquatic ecosystems. High levels of these nutrients cause an overgrowth of plants and algae. As the plants and algae die, they become organic material in the water. The enormous decay of this plant matter, in turn, lowers the oxygen level. The process of rapid plant growth followed by increased activity by decomposers and a depletion of the oxygen level is called eutrophication.
  • Thermal Pollution -- Thermal pollution can occur when water is used as a coolant near a power or industrial plant and then is returned to the aquatic environment at a higher temperature than it was originally. Thermal pollution can lead to a decrease in the dissolved oxygen level in the water while also increasing the biological demand of aquatic organisms for oxygen. 
  • Ecological Pollution -- Ecological pollution takes place when chemical pollution, organic pollution or thermal pollution are caused by nature rather than by human activity. An example of ecological pollution would be an increased rate of siltation of a waterway after a landslide which would increase the amount of sediments in runoff water. Another example would be when a large animal, such as a deer, drowns in a flood and a large amount of organic material is added to the water as a result. Major geological events such as a volcano eruption might also be sources of ecological pollution."



"Water is life. Yet 768 million people do not have access to safe, clean drinking water, and 2.5 billion people (40 out of every 100 people in the world) live without basic sanitation like toilets or places where they can wash their hands. When water is unsafe and sanitation doesn’t exist, contaminated water can kill.

We are lucky in New Zealand because all we have to do is turn our taps on and clean water comes out. In many other parts of the world, women and children are forced to spend large parts of their day fetching water. This time spent collecting water means that children, especially girls, don’t go to school."




Ozone hole and its effect on humans

"Earth has its own layer of sunscreen called the ozone layer, or ozone shield, which makes up part of the stratosphere and absorbs most of the sun’s ultra-violet (UV) radiation. But it doesn’t absorb all of the UV light, and what gets through can cause skin cancer and cataracts in humans as well as reproductive problems in fish, crabs, and frogs.

Since 1983, scientists have observed a scary phenomenon: Earth’s ozone was extremely weak over parts of Antarctica, letting in bouts of harmful UV radiation. The reason, in part, was because a series of man-made chemicals — namely chlorine and bromine — were eating away the planet’s protective, sunscreen-like layer.

They called this weaker region Antarctica’s ozone hole. Although the hole’s size varies each year, it has been consistently larger than 8 million square miles since 1990 — more than twice the size of the entire United States!

In recent years, scientific reports have noted that the hole is slowly healing — thanks to a decrease in ozone-depleting chemicals in the atmosphere — but scientists were not sure when the hole would be completely regenerated.

Now, according to a study published in journal Geophysical Research: Atmospheres, the hole should finally, permanently shrink below 8 million square miles by 2040s and could even be fully recovered by the end of the century.

For the middle half of the 20th Century, companies used ozone-depleting chemicals, called chlorofluorocarbons (CFCs), in refrigerators and aerosol sprays that, through use, were getting released into the atmosphere. By the early ’80s scientists were beginning to understand the damage that these chemicals were doing to the planet.

When CFCs float up to the troposphere, above the ozone, they interact with UV radiation from the sun releasing chlorine, which destroys ozone. As a result of this discovery, an international treaty called the Montreal Protocol was enacted in 1989 that began phasing out the production and subsequent emission of ozone-depleting chemicals.

By that point, however, the damage had been done.

These chemicals can hang out in the atmosphere for years after they have entered the atmosphere. Like a series of dominoes, the ozone hole continued to grow even after CFCs were banned. Here’s a chart showing the size of the ozone hole, in blue, from 1979 through 2012:



Ozone depletion above the planet’s north and south poles was exceptionally bad because Earth’s wind currents were sweeping the chemicals toward either end of the planet.

Once these chemicals reached the poles, a large-scale cyclone, called the polar vortex, was trapping the chemicals where they accumulated over time to high concentrations, ravenously eating away the ozone (see the GIF below). This led to the Antarctic ozone hole as well as the Arctic ozone hole, which in 2011 reportedly had half the ozone it used to."

http://www.businessinsider.com.au/antarctic-ozone-hole-is-healing-2015-5


"Ozone layer is important because it prevents too many harmful ultra violet rays from reaching earth. Ultra violet rays have the capability to destroy plants and animals and can cause skin cancer, cataracts to human beings. Existence of life on earth is possible only because of the presence of ozone layer around the earth.

As of now, the ozone hole remains an area of interest for many. Even though the hole present above the Antarctic is beginning to show signs of a decline, there are concerns regarding the long term effects. In particular, many scientists are worried that the development of the same conditions in other parts of the world may cause large scale ozone thinning in the future, if not ozone depletion all together.

Thinning of ozone layer means getting direct in touch with ultra violet rays which can cause skin cancer or skin irritation which can lead to death. A decrease in 1% of ozone layer can cause 5% increase in cases of skin cancer.

Exposure to UV rays has also increased the cases of cataracts which in turn affects people’s vision and could also cause an increase in people becoming blind."



"Laboratory and epidemiological studies demonstrate that UVB causes nonmelanoma skin cancer and plays a major role in malignant melanoma development. In addition, UVB has been linked to cataracts -- a clouding of the eye’s lens. All sunlight contains some UVB, even with normal stratospheric ozone levels. It is always important to protect your skin and eyes from the sun. Ozone layer depletion increases the amount of UVB and the risk of health effects."



"New Zealand’s death rate from skin cancer is about 300 per year, the highest in the world relative to population (and over half that from road accidents). This is due to the relatively high UV exposures and the high number of fair-skinned people. Peak UV intensities in New Zealand are about 40% greater than at comparable latitudes in Europe.

The UV Index (UVI) represents the intensity of UV radiation. A UVI greater than 10 is extreme, and skin damage can occur in less than 15 minutes. In New Zealand, the midday UVI can exceed 13 in summer. In winter, it rarely exceeds 2, although intensities increase with altitude and when the surface is snow-covered, as on ski fields."



"Skin cancer is the most common cancer in New Zealand. New skin cancers total about 67,000 per year, compared to a total of 16 000 for all other types of cancer. Our skin cancer rates are the highest in the world. In fact, the incidence of melanoma in New Zealand and Australia is around four times higher than in Canada, the US and the UK.

Melanoma cases are reported. In 2011, there were 2204 cases of melanoma in New Zealand. Malignant melanomas more frequently result in death (359 deaths in 2011). Just like other cancers, melanoma is more common in older people, but it is not just an ‘old person’s disease’ – in fact, it is one of the most common types of cancer for 25–44 year olds (15 male and 11 female deaths in 2011). Melanoma is the third most commonly registered cancer in young women and the fourth in young men aged 0-24 years.

Over 90% of skin cancers are due to excess UV exposure in high UV environments like New Zealand. Non-malignant skin cancers are generally found on the exposed parts of the body (such as the face and forearms), and long-term frequent UV exposure is thought to be a predominant cause.

Malignant melanoma risk is linked with an individual’s UV exposure patterns as well as genetic characteristics, like fair skin. Light skin type, a large number of moles and excess sun exposure (particularly episodes of sunburn), especially in childhood and adolescence, are the major predictors of skin cancer risk.

Some reasons for New Zealand’s particularly high skin cancer statistics:

  • The strength of the UV radiation that New Zealand receives – our UV levels are 40% higher during summer than at corresponding latitudes in the northern hemisphere (NIWA research).
  • The low ozone levels – the ozone layer absorbs a good deal of UVB ultraviolet light from the Sun. Any decrease in the ozone layer (such as the ‘ozone hole’ over Antarctica) is expected to increase surface UVB levels. Excessive UVB exposure causes skin cancers such as basal cell carcinomas and squamous cell carcinomas. However, UVA, which is linked to melanoma, is not absorbed by ozone.
  • The significant proportion of the population that has skin types which burn easily (due to our genetic heritage).
  • Our more outdoor lifestyle and tendency to ‘seek the sun’."


"The depleted ozone layer - in part responsible for a 14 per cent jump in melanoma over the past decade - is healing itself.

Melanoma killed almost one New Zealander a day and the rate increased every year."



"The Earth is closer to the Sun during the Southern Hemisphere summer. Our smog-free air also means we have less pollution to block out UVR. Overall peak UVR levels in the New Zealand summer, as measured by the Ultraviolet Index (UVI), are about 40 percent more than at countries at similar latitudes in the Northern Hemisphere. There has also been a 10 percent decrease in ozone over New Zealand since the 1970s."



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