It "blings" my eyes.

Light is very important for human vision. To deal with the limitation of eyes to see in the dark, artificial light is invented.  The lighting improves our physiological performance of vision to detect, perceive and distinguish the existence, size, shape, colour, texture, moving, distance, changes in the brightness or colours, etc. of the objects to be seen. Consequently, the efficiency of the human activities will be increased with the improvement of visual performance.(NARISADA & SCHREUDER, 2004)

What if there is too much lighting than we need?

Light pollution is an unwanted consequence of outdoor lighting and includes such effects as sky glow, light trespass, and glare. (What is light pollution?, 2007)

Figure 1 Useful light vs. light pollution

Source: (What is light pollution?, 2007)

Sky glow:

Sky glow is the result of light that is projected upwards, and then scattered and scattered backby aerosols in the atmosphere to the surface of the Earth. colouring the night sky and reducing the visibility ofastronomical objects.(Mizon, 2002)

Part of the stray light is projected directly upwards due to poorly designed lighting or the light is aimed upwards on purpose. Another major contribution to the stray light is the light that is well-directed to objects, but reflected by them. For example, road surfaces, grass, and buildings reflect a fair amount of the incident light, and the reflected light usually goes upwards.(NARISADA & SCHREUDER, 2004)

Figure 2 Sky glow in Kuala Lumpur, Malaysia

Source: (Morris, 2011)

Light trespass:

Light trespass occurs when spill light is cast where it is not wanted. Light trespass is somewhat subjective because it is difficult to define when, where, and how much light is unwanted. An example of light trespass is when spill light from a streetlight or floodlight enters a window and illuminates an indoor area.(What is light pollution?, 2007)

Figure 3 Light trespass

Source: (LIGHT POLLUTION)

Figure 4 Spill light illuminates the bedroom through window

Source: (The City Dark, 2011)

Glare:

Glare is a visual the sensation produced by luminance within the visual field that is sufficiently greater than the luminance to which the eyes are adapted to. It is subjective, and sensitivity to glare can vary widely. Older people are usually more sensitive to glare due to the aging characteristics of the eye. Disability glare is the reduction in visibility caused by intense light sources in the field of view, while discomfort glare is the sensation of annoyance or even pain induced by overly bright sources. (What is light pollution?, 2007)

Figure 5 Glare

Source: (Rensselaer Polytechnic Institute, 2007)

Effects of light pollution:

Health:

Light pollution is a form of annoyance. According to the World Health Organization, annoyance is described as a feeling of displeasure associated with any agent or condition believed to affect adversely an individual or a group". Annoyance can lead to stress. It depends on the stress level whether the health will be influenced.(NARISADA & SCHREUDER, 2004)

Light pollution is also investigated as a interfering, aggravating factor that suppresses natural melatonin levels in humans at night. This suppression simply pulls out the stops to cancer cell growth. The hormone melatonin normally impedes cancer cell growth and can even cause cancer cell death. (How Light Pollution Affects Human Health)

Animal:

Studies have shown that many animals, like insects and birds, suffer from light at night. Insects are attracted by light. The many insects may attract predators and, in their tum, secondary predators. "Street lighting is on the one hand favorable for predators. Lighting may, however, cause unnatural death"(NARISADA & SCHREUDER, 2004)

Bright lights nearby the beach discourage females from coming ashore to nest. But more important, hatchlings can become disoriented by manmade lighting and fail to find their way quickly to the relative safety of the open sea. The newly hatched sea turtles developed instincts to frenetically crawl toward the lightest horizon, because the ocean breakers would reflect starlight. In the past 100 years, the lighting situation has changed dramatically. Instead of heading directly into the sea, hatchlings go toward the brighter light. Those that wander in circles on the sand have a much higher risk of dying of dehydration, exhaustion or predation. (Hutchinson)

Figure 6 Newly hatched sea turtles wander on the beach

Source: (Hutchinson)

Energy usage, air pollution:

Artificial lighting consumes electricity. We need to burn fossil fuel for the production of electricity, and the by-product of electricity is pollutants. The pollutants include greenhouse gases and toxic chemical that leads to environmental problems such as global warming and they threaten human health. Why do we need to spend money on excess lighting to bring harm to the environment and ourselves?

Safety:

Light can cause confusion or visual distraction that threatens road safety. High levels of glare can also decrease visibility for the road user and increase the risk of road accident.Some of the households over lit their homes to be “safer”. However, overly bright lighting creates a sharp contrast between light and darkness, making the places outside the area of illumination nearly invisible. Bad lighting can even attract criminals by creating deep shadows that offer concealment. (Design Out Crime, 2010)

Figure 7 Security lighting which creates deep contrast. Can you spot the person in the left picture?

Source: (Smit)

Colourful lighting may create beautiful night view. What about the plumes emit from chimney during energy production?

Figure 8 Emission from energy production

Source: (Jones, 2014)

Works Cited

Design Out Crime. (2010, December). Retrieved September 20, 2014, from International Dark-Sky Association: http://www.darksky.org/assets/documents/ida_safety_brochure-bw.pdf

How Light Pollution Affects Human Health. (n.d.). Retrieved September 20, 2014, from Department of Physics, Florida Atlantic University: http://physics.fau.edu/observatory/lightpol-health.html

Hutchinson, L. I. (n.d.). TURNING NIGHT INTO DAY: LIGHT POLLUTION’S IMPACTS ON WILDLIFE. Retrieved September 20, 2014, from Lighting.com: http://lighting.com/light-pollution-wildlife/

Jones, B. (2014, March 13). Energy, Climate Change and Security in the Context of Ukraine: A Discussion with Danish Foreign Minister Martin Lidegaard. Retrieved September 20, 2014, from BROOKINGS: http://www.brookings.edu/blogs/planetpolicy/posts/2014/05/13-lidegaard-europe-energy-ukraine

LIGHT POLLUTION. (n.d.). Retrieved September 20, 2014, from Starlight Theatre: http://www.starlight-theatre.ca/LT-POLLUTION.HTM

Mizon, B. (2002). Light pollution: responses and remedies. London: Springer.

Morris, E. (2011, February 21). Light Pollution in the World. Retrieved September 20, 2014, from Light Pollution and Dark Skies: http://lightpollutionanddarkskies.blogspot.sg/

NARISADA , K., & SCHREUDER, D. (2004). LIGHT POLLUTION HANDBOOK. Netherlands: Springer.

Rensselaer Polytechnic Institute. (2007, February). What is glare? Retrieved September 27, 2014, from Lighting Research Center: http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/glare.asp

Smit, J. (n.d.). Light Pollution—the dark side of light. Retrieved September 20, 2014, from PRETORIA CENTRE OF THE ASTRONOMICAL SOCIETY OF SOUTHERN AFRICA: http://www.pretoria-astronomy.co.za/light_pollution.htm

The City Dark. (2011, August 17). Retrieved September 20, 2014, from Urban Omnibus: http://urbanomnibus.net/2011/08/the-city-dark/

The Woman’s Guide to Buying Flattering Eyewear: When should I Buy New Glasses? (2014, February 13). Retrieved September 20, 2014, from Avoce Eyewear Blog: http://avoceeyewear.com/wp/?p=375

What is light pollution? (2007, February). Retrieved September 20, 2014, from Lighting Research Center: http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/lightPollution.asp

Keep quiet, please!

Noise pollution has not received as much attention as other types of pollution, such as air pollution, or water pollution. This is because the fact that we can’t see, taste or smell it; however, the air around us is constantly filled with sounds. (Noise Pollution, 2012)

Noise is “unwanted or disturbing sound”.  Sound becomes unwanted when it either interferes with normal activities such as sleeping, conversation, or disrupts or diminishes one’s quality of life.  The persistent and escalating sources of sound can often be considered an annoyance. This “annoyance” can have major consequences, primarily to one’s overall health. (Noise Pollution, 2012)

The inner part of the ear contains tiny hair cells. The hair cells change sound into electric signals. Then nerves carry these signals to the brain, which recognizes sound. These tiny hair cells are easily damaged by loud sounds and too much use and it may become damaged. (Vorvick, 2012). The risk of damage to hearing depends on volume which is measured in decibels (dB), duration of exposure (Stony Brook Surgery, 2012) and family history of hearing loss. (Vorvick, 2012)

Figure 1 How sound is transmitted

Source: (Macrae, 2010)

Noise pollution not only causes hearing problems. Nonauditory effects of noise exposure are those effects that don’t cause hearing loss but still can be measured, such as elevated blood pressure, loss of sleep, increased heart rate, cardiovascular constriction, labored breathing, and changes in brain chemistry. According to the WHO Guidelines for Community Noise, “these health effects, in turn, can lead to social handicap, reduced productivity, decreased performance in learning, absenteeism in the workplace and school, increased drug use, and accidents.” (Chepesiuk, 2005)

Noise pollution also affects the ecosystem. It has been found that noise can have a number of impacts on wildlife such as changing patterns of behaviour and effects on breeding patterns. (An Economic Valuation of Noise Pollution – developing a tool for policy appraisal, 2008) For example, increased mortality was observed in fish eggs and embryos located in environments with ambient noise levels that were only 15 dB higher than those observed in nature. (Banner & Hyatt, 1973)

Figure 2 Black-chinned hummingbirds appear drawn to noise, perhaps because their predators, scrub jays, leave noisy sites

Source: (Parry, 2012)

In Singapore’s context, the noise pollution is a common problem from construction sites and Mass Rapid Transit (MRT). Can you imagine the life of residents who have to withstand the noise from MRT trains whizzing by their homes?

One of the operators of MRT train, install noise barrier as mitigation measure. SMRT Trains Ltd (SMRT), have completed installing noise barriers at the new MRT viaduct at Jurong East Station and near Bishan Station. It expects that some 20km of noise barriers may be needed in all to reduce noise pollution from its train network and the installation should be completed by 2020. (Land Transport Master Plan 2013, 2013) The noise barriers will help to reduce noise levels from passing trains by about five to 10 decibels. (REDUCING RAILWAY NOISE, 2013) The current noise guideline adopted to guide developments in the vicinity of MRT tracks is 67 dBA (equivalent continuous noise level over 1 hour) at the facade of building.

Figure 3 Noise barrier installed by SMRT

Source: (Land Transport Master Plan 2013, 2013)

Is the noise level of 67dBA (continuous exposure for 1 hour) safe that it does not cause any health impact?

If a sound reaches 85 dB or stronger, it can cause permanent damage to your hearing. The amount of time you listen to a sound affects how much damage it will cause. The quieter the sound, the longer you can listen to it safely. If the sound is very quiet, it will not cause damage even if you listen to it for a very long time; however, exposure to some common sounds can cause permanent damage. With extended exposure, noises that reach a decibel level of 85 can cause permanent damage to the hair cells in the inner ear, leading to hearing loss. (Decibel Exposure Time Guidelines)

Figure 4 Permissible exposure time for different sound levels

Source: (Decibel Exposure Time Guidelines)

It seems that noise level of MRT is less likely to cause hearing impairment, but it is possible to cause annoyance. The same noise could be annoying to some people but acceptable to others. There is no definite relationship between the degree of annoyance or unpleasantness of noise and the risk of adverse health effects. (Noise - Non-Auditory Effects, 2007)

Maybe for some of the people, the noise produced by MRT is the alarm clock?

Works Cited

Noise - Non-Auditory Effects. (2007, February 16). Retrieved September 19, 2014, from Canadian Centre for Occupational Health and Safety: http://www.ccohs.ca/oshanswers/phys_agents/non_auditory.html

(2008). An Economic Valuation of Noise Pollution – developing a tool for policy appraisal. United Kingdom: Department for Environmental Food and Rural Affairs.

Noise Pollution. (2012, July 16). Retrieved September 12, 2014, from U.S. ENVIRONMENTAL PROTECTION AGENCY: http://www.epa.gov/air/noise.html

(2013). Land Transport Master Plan 2013. Singapore: Land Transport Authority.

REDUCING RAILWAY NOISE. (2013, May 17). Retrieved September 13, 2014, from Land Transport Authority: http://www.lta.gov.sg/content/ltaweb/en/public-transport/mrt-and-lrt-trains/reducing-railway-noise.html

Banner, A., & Hyatt, M. (1973). Effects of Noise on Eggs and Larvae of Two Estuarine Fishes. Transactions of the American Fisheries Society, 102,134-136.

Chepesiuk, R. (2005, January). Decibel Hell: The Effects of Living in a Noisy World. Retrieved September 13, 2014, from National Center for Biotechnology Information: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1253729/

Decibel Exposure Time Guidelines. (n.d.). Retrieved September 14, 2014, from Dangerous Decibels: http://www.dangerousdecibels.org/education/information-center/decibel-exposure-time-guidelines/

Macrae, F. (2010, May 14). Deafness cure breakthrough as scientists create tiny ear hairs from stem cells. Retrieved September 14, 2014, from Daily Mail: http://www.dailymail.co.uk/health/article-1278160/Deafness-cure-breakthrough-scientists-create-tiny-ear-hairs-stem-cells.html

Parry, W. (2012, March 20). Human Racket Affects Plants, Too. Retrieved September 13, 2014, from livescience: http://www.livescience.com/19189-noise-pollution-indirect-effects-plants.html

Stony Brook Surgery. (2012, August 23). Headphones & Earphones Can Cause Permanent Hearing Loss: What You Need to Know. Retrieved September 13, 2014, from Stony Brook School of Medicine: http://medicine.stonybrookmedicine.edu/surgery/blog/headphones-and-earphones-can-cause-permanent-hearing-loss-what-you-need-to-know

Vorvick, L. J. (2012, May 13). Hearing loss and music. Retrieved September 13, 2014, from MedlinePlus: http://www.nlm.nih.gov/medlineplus/ency/patientinstructions/000495.htm

You are causing “pollution” because you look ugly?

There are different types of pollution and visual pollution is one of them, even though it is less known by people. Unlike other types of pollution such as air pollution, water pollution and land pollution which are measurable and quantifiable, how do we define visual pollution since “ugliness” is immeasurable? 

Generally, visual pollution is defined as “any unwanted sight that mentally or physically affects the community or creates any health hazard”. It can be as simple as the ugly scene of huge mountains of waste on the roadside and unpleasant odour that affect your appetite or to a more serious extent which the overload of signboards that distract the road users and causing more road accidents. (Muthukrishnan)

Figure 1 Mountains of rubbish were piling up in the Spanish city of Seville

Source: (Watson, 2013)

Figure 2 Different Forms of Visual Pollution

Source: (Muthukrishnan)

A major conflict between renewable energy and aesthetical value is the wind farm. With the increasing concern of global warming issue, cleaner and more sustainable renewable energy are developed with lesser carbon emission. Wind turbines produce renewable energy by means of transforming wind energy into electricity; the process has no by-product of gaseous emission. (Grimm, 2009) Hence, there is an increase in popularity for wind energy.

World wind energy capacity has been doubling about every three and a half years since 1990.

Figure 3 Comparing Total Wind Energy Generation for 1993 and 2011

Source: (World Energy Resources 2013 Survey, 2013)

Due to the sitting requirements for efficient energy production, wind turbines need to be located in open unobstructed areas where strong winds are prevalent. For economic feasibility, they also need to be located close to a current grid network, reducing huge costs of transmission line connection. Consequently, ideal sitting locations are typically in conspicuous locations within close proximity to the outskirts of residential suburbia. (Grimm, 2009)

Figure 4 Wind Turbines in Natural Landscape

Source: (Terrabotics)

In the form of visual pollution, wind turbines also contribute to shadow flicker. Shadow flicker is defined as alternating changes in light intensity caused by the moving blade casting shadows on the ground and stationary objects, such as window on a dwelling. The major concern for it is the moving visual silhouettes across building windows and possible psychological effects of epilepsy and related health issues. (Grimm, 2009) However, this annoyance can be minimized with careful siting, planting trees or installing window awnings, or curtailing wind turbine operations when certain lighting conditions exist. (Environmental Impacts of Wind Power, 2013)

The video below shows how shadow flicker is caused by wind turbine. Do you think it is annoying?

Source: (http://www.youtube.com/watch?v=MbIe0iUtelQ)

Figure 5 A wind turbine is seen near to a gate of the ancient city of Wushu in Diaobingshan, Liaoning province

Source: (Zhu, 2012)

The wind energy is a form of renewable energy which reduces the impact of air pollution; however, it is hardly avoided to cause the visual pollution. Is wind turbine a nice sculpture for you or do you think it spoiled the beautiful scenery? 

Works Cited

(n.d.). Retrieved September 7, 2014, from Terrabotics: http://terrabotics.co/

Environmental Impacts of Wind Power. (2013, May 3). Retrieved September 7, 2014, from Union of Concerned Scientists: http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/environmental-impacts-wind-power.html

(2013). World Energy Resources 2013 Survey. London: World Energy Council.

Grimm, B. (2009). Quantifying the Visual Effects of Wind Farms; A Theoritical Process in an Evolving Australian Visual Landscape. Retrieved September 7, 2014, from http://digital.library.adelaide.edu.au/dspace/bitstream/2440/63374/2/02main.pdf

Muthukrishnan, N. (n.d.). Visual Pollution - More Dangerous than You Think It Is. Retrieved September 7, 2014, from C.P.R ENVIRONMENTAL EDUCATION CENTRE: http://cpreec.org/161.htm

Watson, L. (2013, February 7). Striking rubbish collectors cause a stink in Seville by letting 6,000 tons of waste pile up on the city's streets. Retrieved September 7, 2014, from CapitalBay: http://www.capitalbay.com/uk/305832-striking-rubbish-collectors-cause-a-stink-in-seville-by-letting-6-000-tons-of-waste-pile-up-on-the-city-s-streets.html

Zhu, C. (2012, September 10). China pushes wind power, but no quick payoff for producers. Retrieved September 7, 2014, from Reuters France: http://reuters.fr/article/newsOne/idUKBRE8880J720120910

Is the water "polluted"?

Today, I will be looking into a study on water pollution. What are the sources of water pollution? What are the indicators to define how “polluted” is the water?

River Sabarmati is one of the biggest and major river of Gujarat that runs through two major cities of Gujarat (a state in the western part of India) (Lodrick, 2014), Gandhinagar and Ahmedabad and finally meets the Gulf of Khambhat (GoK) in the Arabian Sea.

Gujarat is one of the highly industrialized states of India with a strong web of pharmaceutical, petrochemical, textile, automotive, energy, chemical, and other industries. Many of these industries release partially or untreated effluents to the adjoining rivers like the Sabarmati. 

Figure 1 Location of River Sabarmati

Source: (Google Map)

The study of this paper was conducted to evaluate the water quality of this river, as it could possibly be one of the major sources for filling up Kalpasar, the proposed man-made freshwater reservoir supposed to be the biggest one in the world. The Kalpasar would be supplying water for irrigation to 10.54 lakh hectare land in 39 talukas of 6 districts of Saurashtra region; hence the water quality of upstream has the impact on it.

There were total of 9 sampling stations covering 163 km stretch of the river from upstream of Gandhinagar city to Vataman near Sabarmati estuary. (Haldar, et al., 2013)

Figure 2 Nine Sampling Points of the Study

Source: (Haldar, et al., 2013)

	S1	S2	S3	S4	S5	S6	S7	S8	S9
Water temp (°C)	20	19	22	20	27	29	25	25	26.5
pH	8.2	9.2	8.4	8.4	6.8	7.9	8.6	8.9	8.4
Turbidity (NTU)	8.61	41.9	141	3.77	248	48.9	55.7	27.4	74.7
TSS (mg/L)	3.4	29	118	196	9	58	23.2	16.4	40.8
DO (mg/L)	9.44	8.33	8.25	9.73	ND	ND	ND	3.6	ND
BOD (mg/L)	0.91	3.58	2.26	1.32	191.5	42.61	45.8	3.3	50.4
Phenol (μg/L)	17.3	56.2	166.7	70.6	95.4	136.6	250.25	24	57.75
PHC (mg/L)	9.2	8	9.2	3.8	13.8	10.2	235.4	253.2	277.2
TDS (ppt)	0.8	3.7	0.3	0.2	1.9	1.9	2.2	2	1.7
Chloride (g/L)	0.07	1.21	0.21	0.14	0.28	0.43	0.47	0.41	0.35
Salinity (‰)	0.12	1.99	0.25	0.23	0.47	0.70	0.88	0.77	0.67
NO2(mg/L)	0.005	0.015	0.003	0.001	0.005	0.004	0.03	0.02	0.04
NO3(mg/L)	0.046	0.035	0.007	0.005	0.005	0.003	0.02	0.04	0.04
TN (mg/L)	0.12	0.11	0.26	0.04	0.16	0.29	1.8	1.36	1.24
NH4(mg/L)	0.02	0.06	0.12	0.05	0.76	0.45	0.67	0.7	0.49
TP (mg/L)	0.16	0.27	0.25	0.15	0.54	0.38	0.71	0.57	0.6
PO4(mg/L)	0.004	0.03	0.07	0.02	0.24	0.11	0.24	0.23	0.21

Table 1 Tested Result for Different Water Parameters

Source: (Haldar, et al., 2013)

Some of the water parameters discussed:

1.  Dissolved oxygen (DO): DO is the dissolved oxygen which aquatic life breath in. (Kwok, 2011)

·    The higher level of DO at S1 to S4 indicated the high re-aeration rate and rapid aerobic oxidation of biological substances.

·    DO was undetectable in water samples of stations S5 to S7 and S9, indicating that water quality at these stations was not suitable for drinking, outdoor bathing and propagation of wild life according to the classification of Central Pollution Control Board (CPCB) (Annexure I Water Quality Criteria (CPCB) ).

Gujarat Pollution Control Board (GPCB) also performed DO analysis at Sabarmati River and they reported the depletion of DO in the downstream of the river associated with the increase in pollution. (Haldar, et al., 2013) DO is an indicator of pollution because the degradation of organic pollutants decrease the level of DO. (Shifflett)

   

2.  Biochemical Oxygen Demand (BOD): BOD measures the amount of oxygen required or consumed for the microbiological decomposition (oxidation) of organic material in water. (BIOCHEMICAL OXYGEN DEMAND IN WATER BODIES)

·    Acceptable BOD values (<3 mg/l in Indian standard) were observed at stations S1, S2, S3, S4, and S8.

·    Significant high values of 191 mg/l BOD were recorded at station S5, followed by 45.8 and 42.6 mg/l at stations S7 and S6, respectively. The possible reason behind the high BOD is mixing of wastewater from the discharge of effluents from city/towns and industries.

A trend of slight decrease in BOD was observed in the downstream sites, which might be due to the dilution of river water with seawater during high tide. Comparatively, lower BOD values at upstream sampling stations (S1 to S4) than downstream sites clearly suggested the anthropogenic stress over Sabarmati River from Ahmedabad to Vataman.

BOD and DO have significant relationship and directly indicate load of organic pollutants in surface waters.

  

 3.  Total and differential bacterial load:  Bacterial such as Vibrio, coliforms and Streptococcus were measured in the study.  These organisms pose human health hazards. (Palaniappan, et al., 2010)

·    Sampling stations S1 to S4 showed very low total as well as differential bacterial counts.

·    However, there was a drastic increase in total as well as differential bacterial counts at stations S5 and S6 and same trend was noticed for other three downstream stations. (Haldar, et al., 2013)

Table 2 Comparison of Test Result to Different Standards and Rivers (only part of the results are shown)

Source: (Haldar, et al., 2013)

In conclusion, several small and medium-scale industrial estates located nearby the river catchment area are contributing towards the river water pollution. Average concentrations of various components in the Sabarmati River water were comparatively higher than those in different rivers. The data revealed that water at the downstream of the river is not fit for any domestic application. The paper discussed and proved the tremendous influence of anthropogenic activities in the Sabarmati River.

In this study, we could notice the different water parameters were tested and analysed because they are important living condition to aquatic life and human health. There were also correlation between the different water parameters such as the relationship between DO and BOD.

The difference of parameter between different sampling points could be explained by the nearby land use of the sampling points. To determine how “polluted” was the river, the study was compared the different parameters with the standards limit of India and other rivers in the world.

Works Cited

Annexure I Water Quality Criteria (CPCB) . (n.d.). Retrieved 31 August, 2014, from Maharashtra Pollution Control Board: http://mpcb.gov.in/images/pdf/WaterQuality0709/AnnexureI_WQ.pdf

BIOCHEMICAL OXYGEN DEMAND IN WATER BODIES. (n.d.). Retrieved 31 August, 2014, from United Nations: http://www.un.org/esa/sustdev/natlinfo/indicators/methodology_sheets/freshwater/biochemical_oxygen_demand.pdf

Haldar, S., Mandal, S. K., Thorat, R. B., Goel, S., Baxi, K. D., Parmer, N. P., et al. (6 December, 2013). Water pollution of Sabarmati River—a Harbinger to potential disaster. India.

Kwok, C. (2011). Your First Guide to Water Quality Monitoring in Singapore. Retrieved 31 August, 2014, from ABC Waters Learning Trails: http://www.abcwaterslearningtrails.sg/web/files/PUB_WQM.pdf

Lodrick, D. O. (5 May, 2014). Gujarat. Retrieved 31 August, 2014, from Encyclopedia Britannica Logo: http://global.britannica.com/EBchecked/topic/249059/Gujarat

Palaniappan, M., Gleick, P. H., Allen, L., Cohen, M. J., Christian-Smith, J., Smith, C., et al. (March, 2010). Clearing the Waters A focus on water quality solutions. Retrieved 31 August, 2014, from United Nations Environment Programme: http://www.unep.org/PDF/Clearing_the_Waters.pdf

Shifflett, S. D. (n.d.). Water Quality Indicators: Dissolved Oxygen. Retrieved 31 August, 2014, from Water and Sustainability: http://www.unc.edu/~shashi/TablePages/dissolvedoxygen.html