Review Zhang

Occupational Environment and Health Part 1. Occupational Environment 1.1. Concept of Occupational Hazards

Occupational Hazards refer to the occupational factors in the occupational environment or in the occupational process which have negative effects on a worker’s health. The task of occupational hygiene: Recognization of the occupational hazards Evaluation of the occupational hazards Anticipation of the occupational hazards control of the occupational hazards 1.2. Classification of Occupational Hazards 1.2.1. Chemical factors

Classification of chemical factors. Classification depending on their state of aggregation in the atmosphere ① gas ② vapor ③ smoke 1

④ dust ⑤ fog 1.4. Occupational Impariment occupational injuries

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occupational disorders

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work-related diseases occupational diseases

Part 2. Practice of Occupational Medicine 2.1. Preventive work Three Levels of Prevention 

Primary Prevention: refers to the prevention

from disease cause. 

Secondary prevention: or pre-clinical

prevention, refers to the prevention in the very early stage of occupational disease. 

Tertiary prevention:refers to the prevention

in the clinical stage of occupational disease.

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2.2.

Principles

of

Early

Detection

of

Occupational Disease 2.2.1. Workplace environmental monitoring 2.2.2. Health surveillance for people exposed to harmful substances

Preplacement health examination Periodic health examination 2.3. Diagnosis of Occupational diseases The approach including 4 hands: Ⅰ. Exposure Survey of Occupation



Ⅱ. Investigation of Labor Hygiene

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Ⅲ. Clinical signs and symptoms



Ⅳ. Analysis at laboratory

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Part 3.Disease Associated with Exposure to Occupational factors 3.1 Disease Associated with Exposure to Microclimate • heat stroke, • heat syncope, • heat cramp • heat exhaustion. 3.2 Disease Associated with Exposure to noise 3

1. Hearing impairment, noise-induced deafness（ specific action） 2. Neurobehavioral disturbance 3. Cardiac symptom, ECG change 4. Circulatory system disturbance 5. Hypertension

The major features of occupational hypoacusis are initial loss of the hearing function in the region of 4000~8000Hz with further spreading into medium and low frequencies. 3.3 poisoning

If there are several kind of chemical hazards in the occupational environment, they may represent associate function (Multi-toxicant associate function)  Additive

function

Synergistic

function

Antagonistic

function

Independent

function

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benzene：Health Effects:

acute effects： High airborne concentration of benzene results in



CNS depression with acute, non-specific, narcotic effects. It can even cause to death.

Chronic effects： Chronic benzene poisoning can occur with much



lower exposure levels. it can often cause severe bone marrow depression, include changes in blood: anemia, leukopenia, throbocytopenia, and acute myeloid leukemia. Silicosis : What is silicosis? Silicosis is a diffuse, nodular, interstitial pulmonary fibrosis caused by a tissue reaction to inhaled crystalline silica dust. Silicosis : Severity of Disease Depends on: Dust Concentration Percent of free silica Duration of exposure Size of particles ( respirable dust) Silicosis Prevention(“Eight Characters” strategy. ) 5

1. innovation: technological improvement, such as using safe or low-risk materials and more productive processes, and replacing outmoded

productive

methods by

appropriate

advanced

techniques 2. keep it wet: keeping a dusty worksite wet to decrease the concentration of dust, especially for drilling and grinding in mining industries 3.

enclosure:

segregating

workers,

equipment

and

environmental areas to prevent the escape of dust and operators' subsequent contamination 4. ventilation: improving natural and mechanical ventilation 5. protection: providing personal protection for exposed workers 6. supervision: setting up regulations and safe operating rules, and supervising workers to ensure that they follow them strictly 7. education: implementing health and safety education programmes to promote workers' participation and enhance their awareness and skills with regard to personal protection 8. checking up: inspecting the working environments to meet national standards and regularly examining the workers' health in line with national requirements.

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