1 CONSTRUCTION AND DEMOLITION Samuel Nii Tettey (Ergonomist)

2 SESSION OBJECTIVES At the end of the Session, Participants should Know the hazards associated with the construction industry; How these hazards could be controlled

3 INTRODUCTION The construction industry deals with the building, repairing, maintenance, renovation, modification and demolition of houses, airports, offices, factory premises, tunnels, docks, wharfs, seaports, etc. The construction industry is considered to be one of the most hazardous industries in the world of work.

4 INTRODUCTION Contd. Workers of the industry are exposed to a wide variety of safety and health hazards. Exposures differ from job to job and from trade to trade and even from task to task The construction work environment is very dynamic and changes from moment to moment

5 INTRODUCTION Contd. Workers may be exposed to hazards associated directly with their trade (primary) as well as other hazards (secondary) in their immediate environment

6 INTRODUCTION Contd. Construction includes Land demarcation – land identification Excavation Foundation work Brick/civil engineering/etc work Roofing Electrical work Decoration Etc.

7 INTRODUCTION Contd. Each of these stages of work has its peculiar hazards The hazards need be addressed The severity of exposure is a function of the hazard concentration and the duration of exposure

CONSTRUCTION HAZARDS 8

9 HAZARDS OF THE CONSTRUCTION INDUSTRY The hazards of the construction industry may be classified under the following headings: - Physical hazards Biological hazards Psychosocial hazards Chemical hazards Ergonomic hazards

10 PHYSICAL HAZARD Collision Confined Space Slips and trips Falls from heights Struck by objects Workplace transport Equipment – related injury

11 PHYSICAL HAZARD Contd. Physical agents include: - Noise and vibration from construction machinery and equipment Heat and cold (temperatures) Radiation (both ionising and non-ionising) Barometric pressures – hypobaric & hyperbaric pressures

12 PHYSICAL HAZARD Contd. Noise is very much associated with demolition Vehicle engines, winches, rivet guns, pneumatic hammers, power saws, etc. used on construction sites make a lot of noise Heat and cold arise as a result of most construction work being done in the open i.e. workers are exposed to the elements

13 PHYSICAL HAZARD Contd. Exposure to heat or cold may result in hypothermia or hyperglycaemia i.e. heat stress Non-ionising radiation (uv radiation) sources include the sun and electric arc welding Sources of ionising radiation include x- ray equipment used to inspect welds Divers are exposed to high barometric pressure.

14 PHYSICAL HAZARD Contd. Divers may develop certain conditions associated with high pressure including decompression sickness, inert gas narcosis, aseptic bone necrosis among other disorders Falls due to unstable footing, unguarded holes and slips off scaffolding and ladders are very usual

15 BIOLOGICAL HAZARDS Biological exposure are normally due to exposure to infectious micro-organisms, to toxic substances of biological origin or animal attacks Building site clearers and excavators may develop histoplasmosis an infection of the lungs caused by a soil fungus Exposure to contagious diseases – tuberculosis, influenza - from other workers

16 BIOLOGICAL HAZARDS Poison ivy and other plants present toxic substances which can cause skin eruptions Some wood dusts are known carcinogenic while others (e.g. red wood) are allergenic Animal attacks (snake bites, bee stings, etc) due to the disturbance of their habitat is also known Under water workers risk being attacked by sharks or other fish

17 CHEMICAL HAZARDS Chemical hazards in the construction industry normally appear in the form of Dusts Fumes Mists Vapours; or Gases Liquids

18 CHEMICAL HAZARDS Contd. Exposure, therefore, occurs by Inhalation (during normal breathing or smoking) Skin absorbtion (e.g. pesticides for wood preservation, organic solvents) Chemicals may also occur in liquid forms or in semi-liquid form (e.g. glues or adhesives, coal tar) Chemicals may also be ingested with food or with drink Exposure may result in systemic poisoning or organ poisoning e.g. skin dermatitis

19 CHEMICAL HAZARDS Contd. Some illnesses associated with chemical exposure include: - Silicosis among sand blasters, tunnel builders, and rock drillers as a result of exposure to silica dust Asbestosis among demolition worker due to asbestos exposure Bronchitis among welders Skin allergies among masons and others who work with cement Neurologic disorders among painters and others exposed to organic solvents and lead

20 ERGONOMIC HAZARDS Musculoskeletal disorders commonly in the form of sprains and strains are very common among construction workers Other disabling musculoskeletal disorders include tendinitis, carpal tunnel syndrome and low back pain may occur as a result of traumatic injury, repetitive forceful movements, awkward postures or over-exertion Workers assume very awkward postures while at work

21 ERGONOMIC HAZARDS Manual handling characterise a lot of construction work activities The hazards associated with manual handling is therefore very common Poor postures

22 PSYCHOLOGICAL HAZARDS Psychosocial hazards stem from the social organisation of the industry Employment, for example, is intermittent Construction workers have no control over the work they do There is intense pressure to increase productivity Lack of dependable network of social support due to residence away from family

23 CONTROLS Determine first an hazard exposure profile for each worker rather than trade exposure profile Exposure measurements should be based on tasks and not on shifts Tasks are limited activities such as soldering, painting, plumbing, welding, tiling floors, etc. It is important to realise that exposure depends on the hazard concentration, the duration and frequency of exposure

24 CONTROLS Contd. Reduction in exposure may be achieved by reducing concentration, duration and/or frequency of exposure However, administrative controls for reducing duration and/or frequency of exposure is difficult to achieve as exposure is intermittent Exposure is, therefore, best achieved through reduction in concentration

25 CONTROLS Contd. Reduction in concentration is best achieved at source Other factors of consideration in concentration reduction include the work environment as well as the exposed workers

26 CONTROLS Contd. There are three concentration reduction methods. These are, from the best to the least effective are: - Engineering controls at source Environmental controls that remove hazard from the work environment Use of personal protective equipment

27 CONTROLS Contd. Source control can be achieve at the primary source by substitution of a less hazardous for one that is more hazardous. For example, a non-respirable synthetic fibre may be used instead of asbestos Changing process all together For example, replacing pneumatic hammers with impact hammers that are less noisy and vibrate less

28 CONTROLS Contd. Environmental control include the use of local exhaust ventilation (LEV) to remove hazard, especially airborne hazards, from the work environment LEV may be used at a particular job with ventilation duct and a hood LEV used should be mobile due varying position of jobs Shielding may be used to control many radiant physical hazards – noise, arc from welds, ultra violet (UV) light and infra red (IR) radiation and even heat from hot objects Plywood sheets provide protection from UV and IR radiation Sound absorbing and/or reflecting materials may be used to provide protection from noise sources

29 CONTROLS Contd. Personal protective equipment (ppe) may be employed against hazards that do not allow engineering control nor other control measures Fall arrest harnesses may be used to prevent falls during work at heights Training in proper selection, usage, proper fit, and maintenance of ppe are essential factors in any ppe programme Its is important to inform workers of the limitations presented by a ppe Measures should be taken to control any hazard arising out of use of ppe e.g. use of earmuffs and communication problems

NETTING 30