SHS972 – Assignment 1
Workplace exposure standards in Australia are currently recognised by Safe Work Australia (SWA). Safe Work Australia was formerly identified as:
• The Australian Safety and Compensation Council (ASCC), 2005-2009
• The National Occupational Health and Safety Commission (NOHSC), 1985-
NOHSC was initially assigned the task of assessing and setting workplace exposure limits for Australia. The exposure database NOHSC employed was originally obtained from:
• The American Conference of Industrial Hygienists (ACGIH)
• The United Kingdom Health and Safety Executive (HSE)
The initial exposure limits were acquired from these organisations ...view middle of the document...
45 μmol / L (30μg / dL) detailed in part 7.2 of the Model Work Health and Safety Regulations 2011. Exposure limits may also be called up into legislation through standards such as the Adopted National Exposure Standards for Atmospheric Contaminants in the Occupational Environment (NOHSC: 1003, 1995) which is also referred to in chapter 7 of the Regulations 2011.
Question 2: Part A
Dusts in the workplace may have negative effects on the health of workers if inhaled. These dusts range in size from 1μm to 100μm in diameter (Tillman, 2007). ISO 7708:1995 details the three size fractions of dust for health related sampling which are:
• Inhalable fractions: Inhalable fractions have an aerodynamic diameter of less than 100μm. Inhalable dust is airborne material that enters through the nose or mouth and deposits in the respiratory tract.
• Thoracic fractions: Thoracic fractions have an aerodynamic diameter of less than 10μm. This fraction has the ability to enter through the nose and throat and deposit in the respiratory tract and parts of the lungs such as the bronchi.
• Respirable fractions: Respirable fractions have an aerodynamic diameter of less than 5μm. Respirable dust has the ability to penetrate deep into the lungs where gas exchange takes place. As such, respirable dust also has the ability to enter the blood stream through the lungs.
The size of a dust particle depends on the type of material and work process being used.
In terms of health effects, dusts are usually classified as inhalable and respirable for measurement purposes in the workplace. Thoracic fractions are covered by the inhalable fraction.
Inhalable dusts with a large diameter (up to 100μm) deposit in the throat, nose and upper airway. Inhalable dusts can irritate these structures in the airway or have immediate toxic effects. During the past thirty years, wood work has been recognized as a source of respiratory diseases (Monier, Hemery, Demoly, and Dhivert- Donnadieu, 2008). Wood dust is an inhalable dust which can cause adverse health effects in workers including bronchitis, asthma or impaired lung function (Skovsted, Schlünssen, Schaumburg, Wang and Skov, 2000). Due to their larger size, wood dust the particles rarely enter the gas exchange areas of the lung.
The respirable fraction of dust particles are deposited in the gas exchange area of the lungs including the alveoli. Respirable dust particles are associated with chronic and serious health effects. Respirable dust diseases often do not present any instantaneous symptoms and are often the result of exposure over extensive periods of time. Silicosis is an example of respirable lung disease from dust particles below 5μm in size. The hazard profile of respirable crystalline silica dust is similar to other respirable minerals such as asbestos (Busnick, 2011).Silicosis can cause a range of lung diseases including bronchitis, emphysema, chronic obstructive pulmonary disease and silicosis (Busnick, 2011)....