Chapter 13: Occupational Health and Environment

Chapter 13: Occupational Health and Environment

What is occupational health and environment? Occupational health and environment is:

(a) An area concerned with the safety, health and welfare of people engaged in work or employment. 
(b) It deals with all aspects of health and safety in the workplace and has a strong focus on primary prevention of hazards.
(c) It is also a multidisciplinary field of healthcare concerned with enabling an individual to undertake their occupation, in the way that causes least harm to their health.


Why we study on occupational health & environment?

(a) To foster a safe and healthy work environment. 

(b) To protect co-workers, family members, employers, customers,  and many others who might be affected by the workplace    environment.
(c) To give the maintenance and promotion of workers’ health and working capacity.
(d) The improvement of working environment and work to become conducive to safety and health.
(e) To develop the work organizations and working cultures in a direction which supports health and safety at work.

Safety concept:


(source: https://ensnews1.wordpress.com/2016/03/16/national-press-club-hosts-environmental-health-safety-sustainability-roundtable/)

How to apply a safety concept?
To apply the safety concept is by:

(a) Identify: Identify the source of hazards.
(b) Evaluate the problems by:
          - Determine the exposure pathway.
          - Measure the effects.

(c) Control: Controls however possible to prevent from repeating                         again.

Why we have to prevent accident?
There 3 terms of reason that we have to prevent it:

(a) In term of law:
- Based on Occupational Safety & Health Act 1994:
(i) to protect others against risk to safety health
(ii) to establish the National Council for Occupational Safety and           Health.

(b) In term of economic:
- to increase the productivity.
- to increase the profitability.
- to rise the image of certain companies.
- to reduce the fines to certain people.
- to reduce the compensatory damages.

- to reduce investigation time.

(c) In term of morale:
- Worker deserve to be safe from any physical, chemical and        biological danger.
- To aware of their right for ensured their safety and health

- Their welfare was assured by the Occupational Health and Safety   officers.

OHE or KPAS Unit

- It stands for Occupational Health & Environment Unit (Unit    Kesihatan Pekerjaan & Alam Sekitar)
- The main function of OHE is:
(a) to control and coordinates all activities related to occupational health among health personnel and 
(b) environmental health aspect in the community.


This unit was divided into two scope which is: 

(a) Occupational Health:
- to promote health and safety awareness among the employees and responsibility to control and protect themselves from occupational hazards at workplace.
- In still physical &mental strength to employees in connection with the workload to avoid stress at work.

- Continuous monitoring among health personnel who are exposed to hazards at workplace.

-The risk of workers suffering from occupational diseases is:
(i) The type of hazard.
(ii) Duration of exposure.
(iii) The number of hazards exposed.
(iv) Socio-demographic factors (e.g. age, gender, ethnicity and health history)

(v) The use of Personal Protective Equipment.

-The Scope & Activities OH
(i) To establish Safety & Health Committee in health facilities.
(ii) To audit Safety and Health at workplace.
(iii) Conducting risk assessment in all KMM facilities.
(iv) Notify poisoning cases (pesticide/chemicals), occupational injuries (fall, cut, needle-stick Injury) or occupational disease (TB, hearing loss, skin disease, lung disease) among health personnel and investigate the cases.
(v) Audiometry, stress, Hepatitis B Screening.
(vi) Disease Prevention & Control programme.

(vii) To provide training (chemical handling, safety etc.)

(b) Environmental Health Programme

To monitoring & inspection of several organizations such as;
(i) PLKN (national service training program).
(ii) Prison.
(iii) Detention camps.
(iv)Sanitary Inspection at school, market, recreational park, estates residential, farm.
(v) Management of environmental pollution.
(vi) Investigation of open burning and nuisance complaints.
(vii) Inspection of solid waste disposal site.

Regulations Involved:

- Occupational Safety & Health Act 1994 (Act 514)
- Factories and Machinery Act 1967 (Act 139)
- Education Act 1996
- Care Centres Act 993 (Act 506)

- Private Higher Educational Institutions Act 1996

Tools
It commonly practices, in order to assess occupational health and environmental health scope/study:

(i) Occupational health & safety :
- HIRARC: to identify, assess/measure and to control hazard and risk of any workplace and its activities.
- CHRA (DOSH): to be conducted by the employer arising from the use, handling, storage / transportation of chemicals hazardous to health in their workplace.


(ii)Environmental & Health:
-EIA: to identify, predict, evaluate and communicate information about the impact on the environment of a proposed project and to detail out the mitigating measures prior to project approval and implementation.
-HIA: a policy, program or project may be judged as to its potential effects on the health of a population, and the distribution of those effects within the population.
-EHIA (DOE): the process of estimating the potential impact of a chemical, biological, physical or social agent on a specified human population system under a specific set of conditions and for a certain time frame.

Reference:
All the points at above is not mine, it is belong from my lecturer, named Mohd Jamalil Azam Bin Mustafa and please refer the link below: 

https://en.wikipedia.org/wiki/Occupational_safety_and_health

Chapter 12- Air Quality and Pollution

Chapter 12- Air Quality and Pollution

Definition of haze
- Haze is traditionally an atmospheric phenomenon where dust, smoke and other dry particles obscure the clarity of the sky.
- It is caused when sunlight encounters tiny pollution particles in the air. 
- Some light is absorbed by particles while other light is scattered away before it reaches an observer.
- The more the pollutants,the more the absorption and scattering of light, which reduces the clarity and colour of what we see.


                                  (source: http://www.vadscorner.com/internet67.html)

Health Effect of Haze:
- It can affect the heart and lungs, especially in people who already have chronic heart or lung disease e.g. asthma, chronic obstructive pulmonary disease (COPD), or heart failure.

- When inhaled, they can enter the bloodstream and get absorbed by underlying tissue, potentially interacting with other compounds and substances in the body. 

There are 2 term effects of exposure to haze:

(a) Short-term adverse effects of exposure to haze
These symptoms are usually mild and will subside if exposure to haze is limited by staying indoors. It effects are:

- Eye irritation, watering eyes, and/or conjunctivitis (a type of eye inflammation)
- Running nose, stuffy nose, sneezing, and/or post-nasal drip.
- Throat irritation, dry throat, sore throat and/or coughing, phlegm.
- Headache, dizziness, fatigue and/or stress.

(b) Long-term effects of exposure to haze
- A large number of particles in a haze are below 2.5 micrometers in diameter. Therefore these ultra small particles stay in the air longer and are easily carried over long distances, increasing their chances of being inhaled by animals and humans.

- The long-term risks associated with exposure to fine particles:
(i)Faster rate of thickening of the arteries compared to others, promoting the development of vascular diseases.
(ii) Increases the risk of death by cardiovascular disease and reduces life expectancy by several months to a few years.
(iii)May contribute to the development of diabetes.

(iv)Spontaneous abortion, under-weight infants, birth defects and infant death.

How to reduce those terms?

(a) General Measures at the Workplace
- Minimize outdoor activities.
- Identify outdoor work that may be reduced. 
- Close all windows, doors and any openings that may allow haze to enter the workplace.
- Turn on the air conditioner if available. 
- Ensure maintenance of the air conditioner with regular cleaning and servicing.
- Use an air purifier to keep the particulate levels low.
- Provide health education regarding haze to the employees
- Provide respirators for employees who have to work outdoors
- Ensure there is sufficient supply of respirators for employees who have to work outdoors.

(b) General Measures for the Workers
- Inform the management if you are suffering from any heart or respiratory diseases
- Take your medication regularly if suffering from an existing disease, especially heart disease and respiratory diseases.
- Drink more water and increase the intake of fresh fruits and vegetables.
- Cut down on alcohol and coffee.
- Avoid smoking.
- Wear a respirator when you go outside.

Source of air pollution

          (source: http://butane.chem.uiuc.edu/pshapley/environmental/l17/index.html)

There are 2 source air pollution:
(a) Natural resources 

(source: http://www.slideshare.net/MAYANKGUPTA264/impacts-of-air-pollution-on-human-beings)

(b) Anthropogenic sources

(sources: http://www.marlborough.govt.nz/Environment/Air-Quality/What-are-air-pollutants.aspx)




Effect of air pollution:


           (source: http://indiapollutionproject.weebly.com/effects-of-air-pollution.html)

Initiative to overcome air pollution:

(a) Individual initiative
- Car pooled.
- Hybrid vehicles-subsidized.
- NGV.
 -Public transport.
 -4R (Reduce, Reuse, Recycle, Recover)
- Stop open burning.

(b) National initiative
- Support renewable energy such as solar, biofuels, wind & hydroelectric.
- Stop mining fossil fuels.

- Industrial-waste to energy, EIA, best available techniques, ISO 140001 etc.
- R&D on fuel quality
- Intensive for public transport user
- Public awareness-campaigns

- Improve monitoring technology

Legislation on air pollutions:

Environmental Quality Act 1974
(a) Control of Industrial Emissions
- Environment Quality (Clean Air): Regulation 1978
- Environment Quality (Compounding of offences): Rules 1978

(b) Control of Motor Vehicle Emissions
- Environment Quality (Control of lead concentration in Malaysia) Regulations 1985
- Environmental Quality (Motor vehicle Noise): Regulation 1987
- Environmental Quality (Control of emission for diesel engine) Regulations 1996

- Environmental Quality (Control of emission for petrol engine): Regulation 1996

References:
All the points are not mine, it is based the reference that based from:

- Morgan, M.T. (Ed). 2003. Environmental Health. 3rd Edition. Thomson Wadworth. Australia

- W.H. Bassett, 2004. Clay’s Handbook of Environmental Health. Nineteenth edition.
- https://en.wikipedia.org/wiki/Haze

- http://www.healthhub.sg/live-healthy/327/impact_haze_on_health

Chapter 11- Wastewater Management

Chapter 11- Wastewater Management

Definition of waste water and sewage

(a) Waste Water- is any water that has been adversely affected in quality by anthropogenic influence. 

(b) Sewage - a water-carried waste, in solution or suspension, that is intended to be removed from a community such as from domestic or municipal wastewater.


(source: http://sewagetreatment.us/sewage-treatment/sewage-water-sludge-sullage-excreta-sources-waste-water/)

Sewage content:

(a) Organic matter
(b) Nutrients (Nitrogen, Phosphorus, Potassium)
(c) Inorganic matter (dissolved minerals)
(d) Toxic chemicals (heavy metal and pesticides)

(e) Pathogens


Sewage Water Treatment:

The main purpose of water treatment:
- To produce a disposable effluent without causing harm to the surrounding environment and prevent pollution.


                  (source: https://www.halifax.ca/harboursol/WWTFinformation.php)


Individual Septic Tank

- It only provides partial sewage treatment that flows into it and needs to be desludged approximately once in two years.

- Premises with a proper individual septic tank (Malaysian Standards -MS 1228 ) has 3 to 4 rectangular metal covers and is usually located outside the premises.


                     (source: https://www.iwk.com.my/customer/individual-septic-tank)

Why sewage treatment is important?

(a) To improving the environment through proper drainage and disposal of wastewater;
(b) To preventing floods through removal of rainwater;
(c) To preserving receiving water quality.

Sludge:
- Sludge is the accumulated solids produced by a waste water treatment plant and solids left from septage, the liquid pumped from septic tanks.


(source: http://www.gasregister.co.uk/faq/text/additional/What%20is%20sludge/1038/index.htm)

Effluent discharge:
- Must be accomplished without transmitting diseases, endangering aquatic organisms, impairing the soil, or causing unsightly or foul-smelling conditions.
- Effluent standards define what is allowed within the waste waters discharged into the aquatic environment.

- 2 most important parameters are:

(a) Biochemical Oxygen Demand (BOD):
- The amount of oxygen that sewage consumes over a given time. High BOD means, sewage rapidly consume all the naturally-dissolved oxygen in streams, rivers and lakes, thus killing off all aquatic life.

  (source: http://prepareias.in/subject/gs/ecology-and-environment/-biochemical-oxygen-demand)


(b) Suspended Solids (SS):
- The undissolved material in sewage. High SS leads to sludge deposits in the waterways, thus causing significant environmental deterioration.

(source: http://www.fondriest.com/environmental-measurements/parameters/water-quality/turbidity-total-suspended-solids-water-clarity/)


What if it is not treated well?

(a) Health Effects:
- It will contaminate from inhalation, ingestion, or direct contact to human by chemical, microbiological and biological properties of the sewage or sludge.

- The Centers for Disease Control and Prevention (CDC) says sewage workers are not at more risk of Hepatitis A infection than other workers.
- The sewage contain bacteria, fungi, parasites, and viruses that can cause intestinal, lung, and other infections.

- Bacteria such E. coli, shigellosis, typhoid fever, salmonella, and cholera may cause diarrhoea, fever, cramps, and sometimes vomiting, headache, weakness, or loss of appetite.

(b) Environmental Effects:
- Sewage with high concentrations nutrients can be responsible for the formation of algal blooms which reduce light penetration through the water column, may produce toxins and can cause oxygen depletion when decomposition takes place.

Guideline and Legislation

•Environmental Quality (Sewage) Regulations 2009

•Environmental Quality (Industrial Effluent) Regulations 2009

References:
None of the point is mine, you can refer it at the below:

-Delaware Health & Social Services, 2011. Division of Public Health.
- McGraw-Hill Concise Encyclopedia of Engineering. © 2002 by The McGraw-Hill Companies, Inc.
- Morgan, M.T. (Ed). 2003. Environmental Health. 3rdEdition. Thomson Wadworth. Australia
- W.H. Bassett, 2004. Clay’s Handbook of Environmental Health. Nineteenth edition.
- Howard Frumkin, 2005. Environmental Health. From Global to Local.

-UK Marine Special Areas of Conservation. Sewage
- https://en.wikipedia.org/wiki/Wastewater
- https://en.wikipedia.org/wiki/Sewage
http://www.unep.or.jp/Ietc/Publications/Freshwater/FMS10/2importance.asp

- http://www.txpeer.org/toxictour/what_is_sludge.html

Chapter 9: Food Hygiene and Sanitation

CHAPTER 9: FOOD HYGIENE AND SANITATION

I will talk about all the definitions that related with the topic:

(a) Food- Edible or potable substance that consisting of nourishing and nutritive components.

(b) Sanitation- promoting health through prevention of human contact with the hazards of wastes as well as the treatment and proper disposal of sewage or wastewater. 

(c) Cleanliness- that there is absence in physically such as dirt, dust, stains and bad smells.

(d) Food Infection- a microbial infection resulting from ingestion of contaminated foods.

(e) Food Intoxication- type of illness caused by toxins. Under favorable condition certain bacteria produce chemical compounds called toxins.

(f) Food Spoilage- the original nutritional value, texture, flavor of the food are damaged and become harmful to people and unsuitable to eat.

(g) Food borne Illness- A disease that transmitted to people by food.

What is the difference of cleaning and sanitizing?

- Something that looks clean does not mean it is sanitary. Billions of microorganisms may be present even though they are not visible to the naked eye.

- Both cleaning and sanitizing are very important in preventing food-borne illness.


                                         (source: http://slideplayer.com/slide/224190/)


Types of contamination
There are 3 types of food contamination, they are:
(a) Physical- any foreign object that accidentally find its way into food.
(b) Chemical- a chemical substance that can cause food borne illness. It normally found in restaurant.
(c) Biological- it may cause a food borne illness (bacteria, viruses, fungi, parasites, biological toxins)


                        (source: http://www.123rf.com/stock-photo/food_contamination.html)

How to prevent it?
(a) Biological contamination:

- Maintain good personal hygiene
- Observe proper hand washing
- Clean and sanitize equipment
- Maintain clean and sanitize facilities
- Purchase foods only on reputable supplier
- Do not use wild mushrooms
- Control pests

** Cooking does not destroy toxins**

(b) Physical contamination:

- Wear hair cap (man) & veil or cover (woman)
- Avoid wearing jewellery when preparing, cooking and holding foods (ring, earrings)
- Do not carry pencil or pen
- Do not wear nail polish or artificial nails when working with foods.
- Remove staple wire in the receiving area

- Place shields on lights

(c) Chemical contamination:

- Train employees how to use chemicals properly.
- Store chemicals in original containers to prevent accidental misuse.
- Labels are clearly identify chemical contents of chemical containers.
- Wash hands thoroughly after working with chemicals.

- Monitor pest control operator and make sure chemicals do not contaminate foods.

Causes of Food Borne Illness
Three main causes of food borne illness:

1.Cross-Contamination
The process by which bacteria or other microorganisms are unintentionally transferred from one object to another, with harmful effect.

The bacteria can transfer from:
1.Hand to food.
2.Food to food.
3.Equipment to food.

                         (source: https://www.emaze.com/@ALQFLZT/Hospotality)

How to prevent it?
(a) Hand to food:
- Wash hands properly
- Cover cuts, sores and wounds
- Keep fingernails short, unpolished & clean

- Avoid wearing jewellery, except for plain ring.

(b) Food to Food Contamination:
- Separate raw and cooked foods.
- Store cooked foods in the refrigerator on a higher shelf than raw foods.
- Wash fruits & vegetables, in a cold running water.
- Do not let raw meat and raw vegetables be prepared on the same surface at the same time.

(c) Equipment to Food Contamination:
- Use separate cutting boards for different foods
- Prepare raw foods in separate area from fresh and ready to eat foods
- Clean & sanitize equipment, work surfaces & utensils after preparing each foods
- Use specific containers for various food products
- Ensure cloth & towel use for wiping spills are not used for any other purposes

2.Time-Temperature Abuse:
It occurred when:
- Food is not stored, prepared or held at a required temperature
- Food is not cooked or reheated to temperature high enough to kill harmful microorganisms
- Food is not cooled low enough

- Food is prepared in advance and not set to a safe required internal temperature while the food is on hold.


         (source: http://healthinspectorsnotebook.blogspot.my/2015_04_01_archive.html)

How to prevent it?
(a) Cold Holding- Cold foods must be maintained at 41°F or less.

(b) Microwave Cooking- Time and temperature control for safety foods cooked in a microwave must be cooked to 165°F.

(c) Reheating Foods- Food that is reheated must reach a minimum internal temperature of at least 165°F for 15 seconds. Reheating must be done rapidly and the minimum temperature must be reached within two hours.

3.Poor Personal Hygiene
                                       (source: http://slideplayer.com/slide/242674/)
How to prevent it?
(a) Stay Home!
- Stay home if someone is suffering from these illnesses:
i) Hepatitis A
ii) Shigella
iii) E-Coli Infection
iv) Salmonella
* Sick employees must not work with foods*


Food Safety

- Unsafe food causes many acute and life-long diseases, ranging from diarrheal diseases to various forms of cancer.
- Food-borne illnesses are defined as diseases, usually either infectious or toxic in nature,
- It caused by agents that enter the body through the ingestion of food.

Other food safety issues

Other food safety issues are:

(a) Naturally occurring toxins
- Mycotoxins, cyanogenic glycosides and toxins occurring in poisonous mushrooms, periodically cause severe intoxications.

(b) Unconventional agents
- Bovine spongiform encephalopathy (BSE, or "mad cow disease"), is associated with variant Creutzfeldt-Jakob (vCJD) Disease in humans.
- Consumption of bovine products containing brain tissue is the most likely route for transmission.


(c) POPs
- Persistant Organic Pollutants: compounds that accumulate in the environment & human body.
- E.g. Dioxins & PCBs (polychlorinated biphenyls).

(d) Metals
- Lead & mercury, cause neurological damage in infants & children.
- Exposure to cadmium cause kidney damage in elderly.

Food Analysis and Evaluation

(a) HACCP stands for Hazard Analysis Critical Control Point.

- A management tool used to protect the food supply against biological, chemical and physical hazards.
- Purpose: it formally recognize food processing industry to implement and maintain an effective HACCP system for food products.

(b) Food Premises Inspection
-Aim: to examine the status of cleanliness & hygienic of the premises (raw food, storage, preparation, serve and food handler itself).

- It is routine activity undertaken by the District Health Office and Local Authorities.
- They also inspect among school canteen and kitchen, the Institute Higher Education and Training Institutions, plant food, stalls and restaurants in the area of public attention and caterer.

Legislations
(a) Food Act 1983/ Akta Makanan 1983
(b) Peraturan Makanan 1985
(c) Peraturan Makanan (Eksport Ikan) 2009
(d) Peraturan Kebersihatan Makanan 2009
(e) Peraturan Iridiasi Makanan 2011

All the points given above are not mine, some of it based from my lecturer, named Mohd Jamalil Azam Bin Mustafa and please refer the links given below and at the image:

- http://www.businessdictionary.com/definition/food.html
- https://en.wikipedia.org/wiki/Sanitation
- https://simple.wikipedia.org/wiki/Cleanliness

- http://www.extension.umn.edu/food/food-safety/food-service-industry/prep-storage/keep-food-safe-with-time-and-temperature-control/

CHAPTER 10: WATER SUPPLY

CHAPTER 10: WATER SUPPLY

What is the importance of water?

Today, I'll talk about the importance of water. Water is one of the most important substances on earth. All plants and animals must have water to survive. If there was no water there would be no life on earth.

Daily uses of water

                               (source from http://tiffanyolay.com/What-is-Your-WaterMark)


Water-Borne diseases in Malaysia

- 2600 cases of gastroenteritis in Seremban(1982)
- 81 cases of infectious hepatitis in Raub(1987)
- 940 cases of infectious hepatitis in Kota Belud(1988)
- 300 cases of typoidfever in Johor Bahru(1990)
- 1278 cases of cholera in Penang (May 1996)

(Source: Engineering Services Division, Ministry of Health, Malaysia)


Basic components of a water supply system

(source from https://www.tauranga.govt.nz/services/waterdrainage-vehicle-crossings/water-supply/water-supply-system.aspx)

Water Resources

- There are two main sources of drinking water used by human population are: 
(a) surface water
(b) underground water.


- Surface water are from rivers and lakes, groundwater which is stored naturally in underground aquifers.

Water Resources in Malaysia

- In Malaysia, water resources are state matters under the Federal Constitution and policies on management, regulation and development fall under the jurisdiction of the states.

- Various Federal and State agencies are responsible for water resources development and management are mainly focus:
(a) water supply.
(b) irrigation.
(c) hydro power generation.

- In Peninsular Malaysia, the total water resources are dominated by the amount of water that flows in surface streams after rainfall.


- The source of all water is rainfall, with heavy rainfall during the monsoon seasons.

Water Quality Index
- The Department of Environment (DOE) started in 1978 to monitor the river water quality in Malaysia.

- It was initially to establish water quality baseline and subsequently to detect water quality changes, and identify pollution sources.

-River water quality appraisal is based on the Water Quality Index (WQI) such as:
(a) Dissolved Oxygen (DO)
(b) Biochemical Oxygen Demand (BOD)
(c) Chemical Oxygen Demand (COD) 
(d) Ammoniacal Nitrogen (AN)
(e) Suspended Solids (SS)
(f) pH


-It serves as a basis for environmental assessment of a watercourse in relation to pollution categorization and designated classes of beneficial uses.

Water Quality Index in Malaysia


                            (source from http://www.riverbasin.org/index.cfm?&menuid=81)


Water Treatment Plant

-The function of water treatment plant is to remove sediment
and inject chemicals.


(source : http://www.endress.com/en/Endress-Hauser-group/industry-instrumentation-expertise/water-wastewater/water-wastewater-portfolio/wastewater-treatment)

Water Problem and Issues

1. Drought:


- The cause of drought is due of climate changes.
- It can threatens public health and safety.
- There is a need to conserve over the long term to prepare for the uncertainty.

2. Pipe failures- Malaysia’s non-revenue water is currently 39%.

- 26% lost via damaged water pipes
- 6% through inaccurate meter reading
- 5% was stolen

- 2% was due to other reasons.
- It also an increasing problem as pipelines age and reach critical levels of predictable.

3. Water Quality Issues:


-The effect of urbanisation in population activities change the quality of run off within a catchment and its receiving waters.
- If this trend persists, the costs to rehabilitate the river and water treatment facilities will require higher investments.

4. Legislation Issues:


- The lack of effective legislation, institutional arrangements and human resources for the monitoring and control of pollution and the absence of effective cost-recovery systems at the local or national level.

5. Water-borne Diseases:

- Pathogens in water that can cause illness to human and animal.

- Poor sanitation and water supply.

Water Pollution

- Water pollution is the contamination of water bodies (lake, sea or even rivers). 
- This form of environmental degradation occurs when pollutants are directly or indirectly discharged into water bodies without adequate treatment to remove harmful compounds.

Water Quality Parameter
                     (source: http://www.h2okitswaterblog.com/tag/water-quality-testing/)

Source of water pollution came from:

                                (source: http://thankyouocean.org/threats/water-pollution/)



There 2 sources of pollution:
1) Point water pollution source:
- Point sources discharge pollutants at specific locations (direct) through pipelines or sewers into the surface water.


- Examples of point sources are: factories, sewage treatment plants, underground mines, oil wells, oil tankers and agriculture.

                 (source; http://www.slideshare.net/cpelfrey/water-pollution-power-point)

2) Non- point water pollution source:
- Non-point sources are sources that cannot be traced (indirect) to a single site of discharge.

- Examples of non-point sources are: acid deposition from the air, traffic, pollutants that are spread through rivers and pollutants that enter the water through groundwater.


- It is hard to control because the perpetrators cannot be traced.

                              (source: http://mysticriver.org/non-point-source-pollution/)


Major sources of water pollution:
There are 3 major sources of water pollution which are:
(a) Domestic
(b) Agricultural 
(c) Industrial

(a) Domestic
- Wastewater that generated from the household activities.
- It contains organic and inorganic materials such as phosphates and nitrates.

- Organic materials are food and vegetable waste, whereas inorganic materials come from soaps and detergents.

          (source: http://sewagedomesticandindrustrial.weebly.com/domestic-pollution.html)

(b) Agricultural

- Caused by agricultural wastes:
(a) Fertilizers
(b) Pesticides
(c) Soil additives
(d) Antibiotics/drugs
(e) Animal wastes

-It then washed off from the land to the aquatic system through irrigation, rainfall and leaching.

                                      (source: https://www.aadnc-aandc.gc.ca/eng)
(c) Industrial
- It caused by the discharged of industrial effluents.
-The industrial effluents contain organic pollutants and other toxic chemicals.

-Some of the pollutants from industrial source include lead, mercury, asbestos, nitrates, phosphates, oils, etc.


(source: http://postconflict.unep.ch/sudanreport/sudan_website/index_photos_2.php?key=water%20pollution)


                            (source: http://www.eea.europa.eu/themes/water/water-pollution)


Drinking Water Legislation

- Drinking water should be free from any pathogen, virus or fine particles which can cause a disease or bad effect to human bodies.
- WHO’s Guideline for Drinking Water Quality.
- Malaysia National Standard for Drinking Water Quality.



All the points are not mine and some point was from my lecturer named Mohd Jamalil Azam Bin Mustafa, please refer the link at below and at the image:

i)  http://www.health.gov.au/
ii) https://en.wikipedia.org/wiki/Water_pollution

Chapter 8: Environmental Health Toxicology

CHAPTER 8: ENVIRONMENTAL HEALTH TOXICOLOGY

  What really is environmental toxicology and environmental health toxicology? Do you know guys what is toxicology? Today I will define the term of environmental toxicology and environmental health toxicology.

  Environmental toxicology is defined as the study of the fate and effects of chemicals in the environment. It also can be divided into two subcategories which are environmental health toxicology and ecotoxicology.

                        (source from http://www.toxicologyguide.com/886-environmental/)


  Environmental health toxicology is the study of the adverse effects of environmental chemicals on human health. While ecotoxicology involves the study of the adverse effects of toxicants on myriad of organisms that compose ecosystems ranging from microorganisms to top predators.

TYPES OF TOXICANTS:

• Carcinogens: cause cancer (chemical in cigarettes)
• Mutagens: cause mutations in DNA
• Teratogens: cause birth defects (thalidomide)
• Allergens: cause unnecessary immune response
• Neurotoxins: damage nervous system (mercury and lead)

• Endocrine disruptors: interfere with hormones.


      
(source from http://amazingworldfactsnpics.com/health/shocking-ingredients-cigarettes/)



(source from http://logicallaw.tumblr.com/post/87958021501/corporations-cant-just-walk-away-from-10000)
  
It can divided into 2 broad categories:

(a) Toxic- Poisonous
It can be general or very specific and it often harmful even in dilute concentrations.

(b)  Hazardous -Dangerous
It can be flammable, explosive, irritant, acid and very corrosive substance.

EXPOSURE AND SUSCEPTIBILITY
- Airborne toxins always cause more ill health than any other exposure because of the lining of lungs easily absorbs toxins.

-The largest toxin exposure reported in industrial or factories.

- The condition of organism and timing of exposure also have strong influences on toxicity


   
                        (source from http://experttoxicologist.com/toxicology-toxic-exposures.aspx)



Movement, Distribution, and Fate of Toxins

-Solubility is the one of most important characteristics in determining the movement of a toxin.

The chemicals are divided into two major groups:
•Dissolve more readily in water.
•Dissolve more readily in oil.

The water soluble compounds move rapidly through the environment, and have ready access to most human cells.

Bioaccumulation and biomagnification

Bioaccumulation- accumulation of substances in an organism may be passed on to animals that eat the organism up the food chain. 


           (source from http://www.joshgitalis.com/bioaccumulation-what-you-must-know/)


Biomagnifications-  is the increasing concentration of a substance, of a toxic chemical, in the tissues of organisms at successively higher levels in a food chain.


               (source from http://www.slideshare.net/MrJewett/biomagnification-102)


Persistence

The quality of remaining for a long period of time. The persistent chemicals are not easily broken down.

There are 3 persistent Organic Pollutants (POP’s)
- Dichlorodiphenyltrichloroethane (DDT)
- Poly chlorinated biphenyl (PCD)
- Bisphenol A (BPA)

The rate of degradation is affected by:
(a) Temperature
(b) Moisture
(c) Sun exposure

Factors affecting toxicity

Sensitivity of a toxicant can vary with sex, age and weight. Babies, older people, or whom have in poor health are more sensitive or expose to toxicants.

4 type of exposure:

Acute –usually a single exposure for less than 24 hours, which is immediate got a health problem.
Sub-acute –exposure for one month or less.
Sub-chronic –exposure for one to three months.

Chronic –exposure for more than three months, it is very difficult to assess specific health effects due to other factors.

How to determine the dangerous of a chemical?

Type of Effects

i) Local effects –it damage at the site where a chemical first comes into contact with the body; examples are redness, burning and irritation of the skins.

ii)Systemic effects –it adverse the effects that associated with generalized distribution of the chemical throughout the body by bloodstream to internal organ.

iii) Target organ effects –some chemical may confine their effects to specific organ. The most common organs affected by such chemicals are liver, lungs, heart, kidneys, brain and nervous system, and the reproductive system.

References

All the points in this are not mine, please refer it from the book and the links that are listed at bottom below:

i) Robert H. Friss(2012). Essential of Environmental Health. Second Edition. Jones & Bartlett Learning
ii) Jay Withgottand April Lynch (2002). Environmental Health and Toxicology.
iii) Gerald A. Leblanca(2004). Basics of Environmental Toxicology. Textbook of Modern Toxicology, Third Edition, edited by Ernest Hodgson.
iv) Background Information for “Toxicity Testing with California Blackwormsand Alcohol”

v) Stefani D. Hines & Debbie Gevirtzman(2004). Introduction to Toxicology SWEHSC, University of Arizona
vi) https://en.wikipedia.org/wiki/Bioaccumulation
vii) https://en.wikipedia.org/wiki/Biomagnification
viii) https://www.health.ny.gov/environmental/glossary/