MODULE 8:OCCUPATIONAL ENVIROMENTAL HEALTH

MODULE 8:OCCUPATIONAL ENVIROMENTAL HEALTH

Toksikologi adalah kajian berkenaan langkah-langkah rawatan atau kawalan terhadap kesan buruk oleh bahan kimia yang hadir dan bertindakbalas di dalam sesuatu organisma hidup seperti manusia.

Toxicology is the scientific study of the adverse effects of chemicals on living organisms, their actions, their detection and the treatment of conditions produced by them.

Salah satu konsep fundamental di dalam bidang toksikologi ialah konsep Hubungan Dos-Tindakbalas (Dose-Response Relationship).

One of the most important and fundamental concepts in toxicology is the concept of Dose-Response Relationship.

1. Nyatakan definasi Hubungan Dos-Tindakbalas. (1 markah)

Define Dose-Response Relationship. (1 mark)

· Dose-Response Relationship is one of the most important and fundamental concepts in toxicology. This concept says that a dose or a time of exposure of chemical substances will cause an effect (response) on the exposed organism.

· 2 assumptions arising from DR relation

I. There exist a dose with no effect (NOEL)

II. Once maximum effect achieved ,no further effect with increasing dose

2. Nyatakan definasi Paras Dos-Ambang (Threshold Dose Level). (2 markah)

Define Threshold Dose Level. (2 marks)

Threshold Dose Level is increasing of proportionately with the dose for example the higher the dose, the higher the effect. It also means is that below a certain dose, there will be no effect and it may represent a “safe” level of exposure. This dose is called threshold dose. The threshold dose is also referred to as no observed adverse effect level (NOAEL). The dose of substances is the quantity or concentration administered over a period. The quantity of substances is expressed as a weight of a substance for 1kg of body weight. In air, it can be expressed as parts per million or mg/m3.

3. Dos adalah kuantiti atau kepekatan suatu bahan dalam suatu jangka masa yang dinyatakan dalam unit kuantiti = 1 kg dari berat sesuatu organisma; atau kepekatan = ppm atau mg / m3.

Dose of a substance is the quantity or concentration administered over a period. The quantity of a substance is expressed as the weight of the substance for 1 kg of body weight. In air, it can be expressed as parts per million (ppm) or mg / m3.

Walau bagaimanapun, lengkuk Dos-Tindakbalas boleh digambarkan dengan secara umumnya seperti di bawah:

Nonetheless, a dose-response curve can be generally illustrated as below:

y

Responses

Threshold Dose

Dose z

Tandakan 3 parameter yang digunakan di dalam gambarajah lengkuk Dos-Tindakbalas di atas. (3 markah) .Label 3 parameters in the dose-response curve above. (3 marks)

4. Nyatakan definasi LD 50. (1 markah)

Define LD 50. (1 mark)

· Lethal Dose 50 (LD50) is the dose which when administered result in the death of 50% of the population.

5. Di antara bahan kimia di bawah, yang manakah, pada LD 50, yang paling toksik? (1 markah)

Which of these chemicals below, at LD 50, is more toxic? (1 mark)

1. Racun rumput DDT = 113 mg/kg

Grass control DDT = 113 mg/kg

(The answer is A,Grass Control DDT =133mg/kg)

2. Ethyl Alcohol = 1,400 mg/kg

Ethyl Alcohol = 1,400 mg/kg

6. Nyatakan definasi toksikokinetik. (4 markah)

Define toxicokinetics. (4 marks)

· Toxicokinetic (in Greek:”toxicos” meaning poison, and “kinetikos” meaning putting in motion) is a branch of toxicology dedicated to the determination of the fate of substances administered externally to a living organism. Toxicokinetics is often divided into several areas including, but not limited to, the extent and rate of Absorption, Distribution, Metabolism, and Excretion.

· Absorption is the process of a substances entering the body

· Distribution is the dispersion or dissemination of substances throughout the fluid and the tissues of the body

· Metabolism is the transformation of the substances and its daughter metabolite

· Excretion is the elimination of the substances from the body. In rare cases, some drug irreversible accumulate in a tissues in the body

· Toxicokinetic provides information that can assist occupational health practitioners the following areas

· To determine appropriate control measures for chemical

· To determine appropriate biological monitoring test through knowing the fate of chemicals in our body

· To know the target organs affected by the chemicals and to know what to look for when conducting medical surveillance on the exposed workers

7. Dengan mengambil contoh Plumbum atau Timah Hitam (Lead), nyatakan:

By using Lead as the toxicant in your study, determine:

1. Salah satu punca atau sumber plumbum dari industri. (1 markah)

One source of Lead in the industry (1 mark)

· Leaded petrol/batteries

2. Cara kemasukan plumbum ke dalam badan manusia. (3 markah)

The entry routes of Lead into human body. (3 marks)

· Route of entry

I. The lungs by inhalation

II. The skins and mucous membrane by absorption

III. The gastrointestinal tract by ingestion

IV. Puncture wound

3. Berikan 3 jenis sampel dari manusia yang boleh ditentukan paras plumbum. (3 markah)

List 3 types sample which can be taken from human body to determine Lead levels. (3 marks)

· Bone

· Blood (Urine)

· Other organ (Bile ,Sweat ,Hair)

4. Nyatakan salah satu organ dalam badan manusia yang boleh menukarkan sesuatu bahan kimia ke suatu bentuk lain (metabolit). (1 markah)

Name one of the organs in the human body which can change a toxicant into a different metabolite. (1 mark)

· Liver

5. Nyatakan salah satu organ dalam badan manusia yang boleh mengeluarkan (kumuh/excrete) metabolit yang tidak diperlukan oleh badan. (1 markah)

Name one of the organs in the human body which can excrete the metabolite. (1 mark)

· Kidneys

8. Apakah faktor-faktor di antara bahan kimia dan badan manusia yang boleh memberi kesan kepada kesihatan manusia. (13 markah)

What are the factors between a toxicant and a human body which influences the adverse effects of the human health? (13 marks)

· Route of exposure

· Type of chemical involved

· Physical and chemical properties

· The length of exposure time

· Concentration of exposure

· Effect of chemical interaction

· Age

· Sex

· Atomic

· Genetic make up

· Immunological status

· Nitritional satus

· Concurent disease

9. Nyatakan 4 jenis kesan kronik sesuatu bahan kimia. (4 markah)

List 4 types of chronic effects of a toxicant. (4 marks)

· Carcinogenicity

· Mutagenicity

· Teratogenicity

· Reproductive Organ Damage