CHAPTER 13:OCCUPATIONAL HEALTH AND ENVIRONMENT

Assalamualaikum guys so today we disscus about occupational health and environment.

What is Occupational Health And Environment?

a)Occupational health and environment is an area concerned with the safety,health,walfare of people engaged in work or employment.

b)occupational health deals with all aspects of health and safety in workplace and has a strong focus on primary prevention of hazards.

Why we study on occupational health&environment.

a)To foster a safe and healthy work environment
b)Protect co-workers,family members,employers,customers and many others who might affected by the workplace environment.

Why we must prevent accident
There are 3 terms to prevent accident

Law
Based on the Occupatinal Safety & health Act 1994
-to protect others against risk to safety health
-to establish the National Council for Occupational Safety and Health

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 investigation time

Morale
-workers deserve to be safe
-aware from their right
-their walfare was assured  by the Occupational Health and Safety Officer.

OHE or KPAS Unit

-Occupational Health & Environment Unit (Unit Kesihatan Pekerjaan & Alam Sekitar)
-to control and coordinates all activities related to occupational health among health personnel and environmental health aspect in the community.

This unit devided by two scope which is;

Occupational Health.
-Promote health & safety awareness among the employees and responsibility to control and protect themselves from occupational hazards at workplace.

-Instill 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.

Risk of  Occupational Health 

The risk of workers suffering from occupational diseases is dependent on the following factors;
a)The type of hazard
b)duration of exposure
c)the number of hazard exposed
d)socio-demographic factors(e.g. age ,gender ,ethnicity and health history)
e)The use of PPE (Personal Protective Equipment)

The scope &activities OH

1. Establish Safety & Health Committee in health facilities
2. Audit Safety and Health at workplace
3. Conducting risk assessment in all KMM facilities
4. 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.
5. Audiometry, stress, Hepatitis B Screening
6. Disease Prevention & Control programme
7. Provide training (chemical handling, safety etc.)

Monitoring & inspection of several organization such as:

1. PLKN (national service training program) 
2. Prison '
3. Detention camps 
4. Sanitary Inspection at school, market, recreational park, estates residential, farm 
5. Management of environmental pollution 
6. Investigation of open burning  and nuisance complaints 
7. Inspection of solid waste disposal sit
8.inspection of building plan/renovation/sewerage plan
9.building inspection for Certificate of Fitness For Occupancy(CFO) .
10.cementary inspection
11.certificate of import/export of body parts or corpse,body ashes.
12. inspection of TASKA,TADIKA, /TABIKA,University and colleges.

Regulation Involved

1. Occupational Safety & Health Act 1994 (Act 514)
2. Factories and Machinery Act 1967 (Act 139)
3. Education Act 1996
4. Care Centres Act 993 (Act 506)
5. Private Higher Educational Institutions Act 1996

Tools

Commonly practices, in order to assess occupational health and environmental health scope/study;

• Occupational health & safety – HIRARC, CHRA (DOSH)
• Environmental & Health – EIA, HIA, EHIA (DOE)

HIRARC

HIRARC is an integration tool to identify, assess/measure and to control hazard and risk of any workplace and its activities.

CHRA

The Chemical Health Risk Assessment (CHRA) is an assessment that has to be conducted by the employer arising from the use, handling, storage or transportation of chemicals hazardous to health in their workplace.

EIA

-Environmental Impact Assessment (EIA) is a study 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 or EHIA

• WHO defines HIA as “a combination of procedures methods and tools by which 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,”

• HIA is 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 timeframe.

Reference
(all this notes based on our lecturer, Sir Mohd Jamalil Azam)
(https://en.wikipedia.org/wiki/Occupational_safety_and_health)

CHAPTER 12: AIR QUALITY AND POLLUTANT

Assalamualaikum guys and hye so today we talk about air quality and pollutant.

Definition haze

a)haze is fine dust,smoke, or light vapor causing lack of transparency of the air.

b) a cloudy appearance in a transparent liquid or solid; also:dullness of finish

c)Haze 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 observe.



(source:http://cdn.theborneopost.com/newsimages/2015/10/C_PC00089501.jpg)

Health Effects of Haze

a) The small particles that cause haze are composed of microscopic solids or liquid droplets that are so small that they can get deep into the lungs and cause serious health problems

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

Short term adverse effects of exposure to haze

• 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

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

1)The long-term risks associated with exposure to fine particles:
 a) Faster rate of thickening of the arteries compared to others, promoting the development of vascular diseases.

b)Increases the risk of death by cardiovascular disease and reduces life expectancy by several months to a few years.

c)May contribute to the development of diabetes

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

General Measures at the workplace.

-Minimize outdoor activities.
Identify outdoor work that may be reduced
-Turn on air comditioner if available.
-Ensure maintenance of the air conditioner with regular cleaning and servicing
-Use an air purifier to keep the particulate levels low.

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.
-This helps the body to flush out toxins absorbed through the skin and lungs, and improve the immune system. • Cut down on alcohol and coffee
-These promote fluid and nutrient loss from the body.
• Avoid smoking
• Wear a respirator when you go outside.

Source pollution devided by two which is natural and anthropogenic

Natural
Dust storm
Forest fire
Volcanic eruption

Anthropogenic
Transportation
Residential
Agriculture
Industrial

Individual initiative
-car pooled
-hybrid vehicles-subsidized
-NGV
-Public transport
-4R(Reduce,Reuse,Recycle,Recover)
-Stop open burning

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.
• Strengthen the enforcement (JPJ, Puspakom, DOE, any related agencies)
• R&D on fuel quality
• Intensive for public transport user
• Public awareness-campaigns
• Improve monitoring technology.

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

• 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
http://www.merriam-webster.com/dictionary/haze
(these notes based on my lecturer's note, Sir Mohd Jamalil Azam bin Mustafa)

CHAPTER 11: WASTEWATER MANAGEMENT

Assalamualaikum ,today the topic is about wastewater management. What is waste water? So today we discuss about it.

Definition of Wastewater and Sewage

Waste water: Waste Water is any water that has been adversely affected in quality by anthropogenic influence.

1) It comprises liquid waste discharged by domestic residences, commercial properties, industry, and/or agriculture and can encompass a wide range of potential contaminants and concentrations.

Sewage:means any liquid waste or wastewater discharge containing human, animal, domestic, or putrescible matter in suspension or solution, and includes liquids containing chemicals in solution either in the raw, treated or partially treated form.

Sewage Content

a) organic matter
b)nutrients(nitrogen,phosphorus,potassium)
c)inorganic matter(dissolved mineral)
d)toxic chemical(heavy metal,pesticides
e)pathogens

Sewage treatment

The objective is to produce a disposable effluent without causing harm to the surrounding environment &prevent pollution.


(source:http://www.unitedenvirotech.com/wp-content/uploads/2014/10/changyi51.jpg)

Individual Septic Tank

1) 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.

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



(source:https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiDkwqcI30GyqfQYWNPTFj6D0FeO_iRobmtNIWpzBOobt97MhlPNdbUMmOLUZzuCEOqxxM8McI78pk9vkuxFHkZ8bl_VvFSpZQm5NU_gb_NaBdhIEd0ppzZ9E4gETfyEWqghQDTWBwRgU/s640/11406135_810290705734596_2398179276497608938_o.jpg)

Why treat sewage?

1)Because environmentally-safe fluid waste stream and a solid waste suitable for disposal or reuse (usually as farm fertilizer).

2) Using advanced technology it is now possible to re-use sewage effluent for drinking water

Sludge

1)Residual, semi-solid material left from sewage treatment processes or settled suspension from conventional drinking water treatment

2)Untreated sludge is a significant environmental & public health hazard.

3) Treated stabilized sludge is inert, stable and safe to use.



(source: http://www.apateq.com/img/thumb/shutterstock_142164307_small.jpg)

Effluent discharge

1) Must be accomplished without transmitting diseases, endangering aquatic organisms, impairing the soil, or causing unsightly or foul-smelling conditions

2) Effluent standards define what is allowed within the wastewaters discharged into the aquatic environment.

3) 2 most important parameters are Biochemical Oxygen Demand (BOD) and Suspended Solids (SS)

4) BOD - 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

5) SS - undissolved material in sewage. High SS leads to sludge deposits in the waterways, thus causing significant environmental deterioration

Health effects

1)Contaminate via inhalation, ingestion, or direct contact to human by chemical, microbiological and biological properties of the sewage or sludge

2) The Centers for Disease Control and Prevention (CDC) says sewage workers are not at more risk of Hepatitis A infection than other workers

3) Sewage contain bacteria, fungi, parasites, and viruses that can cause intestinal, lung, and other infections

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

Environmental Effects

Nutrient enrichment: 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

a)Environmental Quality (Sewage) Regulations 2009
b)Environmental Quality (Industrial Effluent) Regulations 2009

Reference
(All these notes based on my lecturer's note, Sir Mohd Jamalil Azam bin Mustafa)

CHAPTER 10: WATER SUPPLY

Assalamualaikum,hye guys , so today we will discuss about water supply. Why water is importance to human. So there is.



(source: http://www.ddcwsa.com/wp-content/uploads/2014/07/dailywaterusechart1.jpg)

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 typoid fever in Johor Bahru (1990)
• 1278 cases of cholera in Penang (May 1996)

Basic component of a water supply system

Water resources ~> Treatment facilities~> water moving mechanism~>system distribution.

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 – mainly water supply, irrigation and hydropower 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.


(Source:http://images.slideplayer.com/16/5175607/slides/slide_21.jpg)

Water Quality Monitaring

• Monitoring of river water quality in Malaysia by the Department of Environment (DOE) started in 1978

>initially to establish water quality baseline and subsequently to detect water quality changes and identify pollution sources.

Water quality index (WQI)

>River water quality appraisal is based on the Water Quality Index (WQI)

~ Dissolved Oxygen (DO) 

~ Biochemical Oxygen Demand (BOD) 

~ Chemical Oxygen Demand (COD) 

~ Ammoniacal Nitrogen (AN) 

~ Suspended Solids (SS) 

~ pH

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

Water treatment plant

Water treatment plant are designed to remove sediment and inject chemicals.

(source:http://cof-cof.ca/wp-content/uploads/2012/03/Surface-Water-Treatment-Plant.gif)

Moving the water

Three primary methods of moving water throughout the water supply system

• Gravity
• Direct pumping
• Combination

Water Issues&Problems

Drought

• The cause of drought – climate changes
• it threatens public health and safety
• There is a need to conserve over the long term to prepare for the uncertainty.

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.

Pipe failures are an increasing problem as pipelines age and reach critical levels of predictable. 

Water Quality issues

>The effect of urbanisation/increase in population activities change the quality of runoff within a catchment and its receiving waters

>Sedimentation of rivers from land development & clearing degrade water quality and affect the natural channel

>Rainfall washes contaminants into the storm water system whereby they are transported to receiving waters.

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.

Water-borne diseases

>Pathogens in water that can cause illness to human or animal.

>Poor sanitation and water supply.

Water Pollution

>The water which has contains and condition changed, not suitable to use

>Any chemical, physical or biological change in the quality of water that has a harmful effect on any living thing that drinks or uses or lives (in) it.

Water Quality Parameters

(Source:http://image.slidesharecdn.com/coolingwatertreatment-150828121308-lva1-app6891/95/cooling-water-treatment-4-638.jpg?cb=1440764189)

(source:http://image.slidesharecdn.com/water-pollution-and-treatment-1234887888240184-1/95/water-pollution-and-treatment-4-728.jpg?cb=1234866315)

There are two sources of pollution

1.Point source.

Point sources discharge pollutants at specific locations (direct) through pipelines or sewers into the surface water.

Example:factories, sewage treatment plants, underground mines, oil wells, oil tankers and agriculture.

2.Non point source.

Non-point sources are sources that cannot be traced (indirect) to a single site of discharge

Example:acid deposition from the air, traffic, pollutants that are spread through rivers and pollutants that enter the water through groundwater.

*Non-point pollution is hard to control because the perpetrators cannot be traced*

(source:http://oceanservice.noaa.gov/education/kits/pollution/media/pol04a_460.jpg)

There are three major sources

Domestic

Agricultural

Industrial

Domestic

 >Wastewater 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:https://usercontent1.hubstatic.com/6791840_f520.jpg)

Industrial Pollutants

>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://www.crwater.com/wp-content/uploads/CWA1.png)

Agricultural Pollutants

Caused by agricultural wastes

Example: • Fertilizers • Pesticides • Soil additives • Antibiotics/drugs • Animal wastes

(source:http://d2ouvy59p0dg6k.cloudfront.net/img/pesticides_39194_363774.jpg)

(source:https://www.epa.gov/sites/production/files/styles/large/public/2013-06/cows_web.jpg)

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.

Reference

(All these notes based on my lecturer's note, Sir Mohd Jamalil Azam bin Mustafa)

CHAPTER 9: FOOD HYGIENE AND SANITATION

              So today will discuss about food hygiene and sanitation . 

 Food hygiene divided by two which is by induvidual and by food industry

Individual=Food borne illness could result to illness or diseases that could affect overall health, work and personal lives.

• Loss of family income 

• Increased insurance

• Medical expenses 

• Cost of special dietary needs

• Loss of productivity, leisure and travel opportunities 

• Death or funeral expense

Food Industry – Food borne illness outbreak can cost thousands ringgit loss, or even be the reason to closed the business. 

• Loss of customers and sales

• Loss of reputation

• Lawsuits 

• Lowered employee morale 

• Employee absenteeism

• Increase employee turn over 

• Embarrassment 

 

Definition food:

Any substance whether solid, semi-solid or liquid that is consume by human

Definition Sanitation:

Being clean and conducive to health

Definition cleanliness:

Absence of visible dirt and not necessarily sanitized

Definition food infection:

Microbial infection resulting from ingestion of contaminated foods.

Definition intoxication:

type of illness caused by toxins. Under favorable condition certain bacteria produce chemical compounds called toxins.

Definition food spoilage:

 The original nutritional value, texture, flavor of the food are damaged and become harmful to people and unsuitable to eat.

Definition borne ilness:

 A disease transmitted to people by food.

Difference between cleaning and sanitizig

-Cleaning removes the visible soil and food particles from a surface.

-Sanitizing reduces the number of microorganisms (bacteria, viruses, etc.)

Cleaning Vs 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 essential in preventing foodborne illness.

Types of contaminants And preventation

1. Biological Contaminant
2. Physical   Contaminant
3. Chemical Contaminant

Biological contaminant

May cause a food borne illness (bacteria, viruses, fungi, parasites, biological toxins)

Ex: • Sea food toxins • Mushroom toxins • Clostridium Botulinum • Salmonella bacteria.

Prevention

• 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

Physical contaminant

Any foreign object that accidentally find its way into food

 • Staple wire • Dust • Metal shavings • Nails • Earrings • Hair clips • Plastics • Metal

• Glass fragments • Insects • stones

Prevention

 

-Wear hair cap(men) or veil(women)

-Avoid wearing jewelry 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

Chemical contaminant

A chemical substance that can cause food borne illness. Substances normally found in restaurant

Ex; • Toxic metals • Pesticides • Cleaning product • Sanitizers • Preservatives

Prevention

• Train employees how to use chemicals 

• 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. There are three main causes of food borne illness

1. Cross- Contamination 

2. Time-Temperature Abuse 

3. Poor Personal Hygiene

 

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

Prevention Hand to food

• Wash hands properly 

• Cover cuts, sores and wounds 

• Keep fingernails short, unpolished & clean 

• Avoid wearing jewelry, except for plain ring

\

Source:(http://image.slidesharecdn.com/chapter1-120619163656-phpapp02/95/food-sanitation-safety-hygiene-chapter-1-23-728.jpg?cb=1340123904)

Food to Food contaminatios

• 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

Equipments to food contaminants

• 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

Time-temperature abuse

• 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

Good personal hygienes

• Medicines should be kept inside the locker and away from foods 

• Clean and cover cuts and wounds 

• Never use bare hands when handling ready to eat foods

Hygienes requiments

Food handlers must:

 • wash their hands whenever they are likely to be a source of contamination (after using the toilet, smoking, coughing, sneezing, using a handkerchief, eating, drinking or touching the hair, scalp or body)

• take all practicable measures to prevent unnecessary contact with ready-to-eat food.

Employer responsibilities:A food business must:

• ensure food handlers do not handle food if there is a possibility of contamination

• maintain easily accessible hand washing facilities and supplies of hot running water, soap and single-use paper towel

Reference

(All these notes based on my lecturer's note, Sir Mohd Jamalil Azam bin Mustafa)

CHAPTER 8: ENVIRONMENTAL TOXICOLOGY

   What is environmental toxicology and environmental health toxicology?Today i will discuss about it.

   Environmental toxicology is defined as the study of the fate and effects of chemicals in the environment, while environmental health toxicology defined as the study of the adverse effects of environmental chemicals on human health, while ecotoxicology focuses upon the effects of environmental contaminants upon ecosystems and constituents thereof (fish, wildlife, etc.).

  Rinse of synthetics chemicals
  
    There has been widespread synthetic chemical production since WWII. People were largely unaware of the health risks of many toxicants. The potent insecticide DDT was sprayed widely in public areas, even on people.Further research led the EPA to ban DDT in 1973. These developments were central to the modern environmental movement. So the world right now stop using DDT.

Types of toxicants 

 • Carcinogens: cause cancer
 • Mutagens: cause mutations in DNA
 • Teratogens: cause birth defects
 • Allergens: cause unnecessary immune response
 • Neurotoxins: damage nervous system
 • Endocrine disruptors: interfere with hormones

Toxicology is dangerous chemicals, these chemicals divided by two broad categories:

   Toxic - Poisonous
 • Can be general or very specific. Often harmful even in dilute concentrations.
   Hazardous - Dangerous
 • Flammable, explosive, irritant, acid, corrosive

Toxic chemicals

 • Allergens - Substances that activate the immune system.
 • Antigens -Allergens that are recognized as foreign by white blood cells and stimulate the production of specific antibodies.
 • Other allergens act indirectly by binding to other materials so they become antigenic.
 • Sick Building Syndrome

  Endocrine Disrupters disrupt normal hormone functions.
 • Thyroxine • Insulin • Adrenalin • Endorphins

   Neurotoxins - Metabolic poisons that specifically attack nerve cells.
 • Different types act in different ways.
 • Heavy Metals kill nerve cells.
 • Anesthetics and Chlorinated Hydrocarbons disrupt nerve cell membranes.
 • Organophosphates and Carbamates inhibit signal transmission between nerve cells.

Mutagens -Agents that damage or alter genetic material.
 • Radiation.

Teratogens - Specifically cause abnormalities during embryonic growth and development.
• Alcohol - Fetal Alcohol Syndrom

Carcinogens - Substances that cause cancer.
 • Cigarette smoke

Exposure and susceptibility

• Airborne toxins generally cause more ill health than any other exposure (lining of lungs easily absorbs toxins)
• Largest toxin exposure reported in industrial settings.
• Condition of organism and timing of exposure also have strong influences on toxicity.

Exposure routes 

• Ingestion – chemicals can enter the body by eating or drinking
• Inhalation – chemicals can be breathed into the lungs
• Absorption - chemicals can enter the body by moving through the skin

Factor affecting toxicity

• Not all people are equal.  Sensitivity to a toxicant can vary with sex, age, weight, and so forth.
• The more sensitive is actually babies.older people and poor health

Types of exposure

• Acute – usually a single exposure for less than 24 hours (immediate 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 (very difficult to assess specific health effects due to other factors)

Mixture of toxicants 

• Substances may interact when combined together
• Mixes of toxicants may cause effects greater than the sum of their individual effects. These are called synergistic effects.
• A challenging problem for toxicology: There is no way to test all possible combinations! (And the environment contains complex mixtures of many toxicants.)

Mechanisms for minimizing toxic effects

Every material can be poisonous under certain conditions.

 • Most chemicals have a safe threshold under which their effects are insignificant.

Metabolic Degradation
• The liver is the primary site of detoxification of both natural and introduced poisons.

Excretion and repair

Effects of waste products and environmental toxins reduced by eliminating via excretion. • Breathing • Kidneys (Urine)

Tissues and organs often have mechanisms for damage repair.
 • Any irritating agent can be potentially carcinogenic

Types of effects

• Local effects – damage at the site where a chemical first comes into contact with the body; examples are redness, burning and irritation of the skins
•  Systemic effects – adverse effects associated with generalized distribution of the chemical throughout the body by bloodstream to internal organ.
• 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

Reference

(All these notes based on my lecturer's note, Sir Mohd Jamalil Azam bin Mustafa)

CHAPTER 6: VECTORS CONTROL

Assalamualaikum,guys hehe so hari ni bab 6

Apakah vektor? So sya akan terangkan

   Vektor ialah haiwan atau serangga yang membawa  penyakit kepada manusia. Manakala pest pula penggangu,perosak,haiwan perosak atau benda yang selalu membuat kacau.

  Vektor juga dikenali kerana membawa sesuatu agen ke host berdasarkan epidemiology triangle. Tak semua vektor adalah pets, tak semua juga pest adalah pest.

 Terdapat beberapa contoh vektor ialah rodents(tikus), lipas nyamuk,lalat,fleas(kutu tikus), dan kutu

JENIS RADENTS DAN PEST

RADENTS ialah yang bercirikan dua batang gigi acip yang sentiasa memanjang di rahang atas dan bawah, tetapi sentiasa dirapikan dengan menggerogot. Contohnya, tikus tupai,hamster dan sebagainya. Masalah nya merosakkan harta benda, membawa fleas, plague, dan kencing tikus.

Terdapat beberapa 'commensal rodents'

ROOF RATS 




(source:www.doyourownpestcontrol.com)


HOUSE MICE




(source:www.proofpest.com)




NORWAY RATS 




(source:nobuggy.com)

ARTHROPODS

MAKSUD:JOINTED FOOT (banyak kaki)


Serangga, kelas terbesar artropod , mempunyai 3 pasang kaki , badan dibahagikan dengan kepala , toraks dan abdomen , ditambah bahagian mulut yang terdiri daripada palpi dan proboscis.
Contohnya: nyamuk,lalat,lipas,fleas ,dan kutu

Nyamuk mempunyai 4 peringkat iaitu



(source:http://www.ocvcd.org/images/mosquitoes/mosquitoLifeCycle.png)

nyamuk membawa penyakit iaitu denggi, malaria demam kuning,chikungunya and filariasis. Nyamuk juga aktif subuh dan senja iaitu nyamuk aedes. Perbezaan nyamuk betina dan jantan ialah nyamuk betina menghisap darah untuk menghasilkan telur manakala nyamuk jantan pula memakan jus buah.

LALAT





(source:http:www.getridoffliesguide.com)

lalat menyebarkan penyakit dan merosakkan makanan. Seluruh badan lalat mempunyai penyakit. Lalat selalaunya di kawasan taman perumahan,ladang ternakan,proses makanan,tempat penyembelihan dan pasar.

LIPAS

Lipas suka berada di kawasan celah celah dan ruang contohnya di celah almari. Lipas menyebarkan penyakit melalui kaki dan muntah. Lipas juga aktif pada waktu malam, sebab tu malam je mesti banyak lipas :P.

3 Jenis Lipas

American cockroach



(source: https://upload.wikimedia.org/wikipedia/commons/3/3b/American-cockroach.jpg)


German cockroach



(source :http://entomology.ifas.ufl.edu/creatures/urban/roaches/german_cockroach06.JPG)

Oriental cockroach



(source:http://entomology.ifas.ufl.edu/creatures/urban/roaches/oriental_cockroach01.JPG)

Yang selalunya berada di rumah kita ialah american cockroach. Tugas lipas suka merosakkan harta benda .*lipas susah nak mati*

FLEAS


Fleas selalunya kat haiwan peliharaan. Membawa dan menghantar alergen dan penyakit menerusi manusia melalui haiwan apabila di gigit.





(source:http://www.our-happy-cat.com/images/cat-flea-dirts.jpg)




(Source:http://www.pesticideresearch.com/site/wp-content/uploads/2012/08/FleasLifeCycle.gif)


Terdapat 4 cara vektor dan pest control

Biological
Physical
Cultural
Chemical

Kaedah physical ialah tapping menepuk. Manakala Cultural pula dari segi pembersihan. Kaedah biological pula parasit atau pemangsa untuk membasmi perosak tertentu. Dari segi kimia pula menggunakan racun perosak yang sesuai.

*notes based on my lecturer's note, Sir Mohd Jamalil Azam bin Mustafa*
*http://hidayatmy.blogspot.my/2011/08/apakah-itu-rodent.html*