B7.1 Reducing the health impacts of dust
Most wind driven dust occurs within a metre of the ground and causes the majority of problems.
Data show that 81% of surveyed houses had a fenced yard. Fences will help protect and support yard planting, control vehicular access, limit animal access and all these in combination will reduce dust.
Only 32% of houses had any effective windbreak planting to reduce the movement of dust in the yard – this was a rise of 5% since 2013. Despite the low windbreak planting result, 98% of houses had at least one working yard tap available to assist in irrigating dust control planting.
Where roads or the edges of a road are not sealed, cars may generate high levels of dust. If the house yard is not fenced, it will be hard to control the movement of vehicles around the house or to establish any landscaping. Survey data shows that 50% of houses had at least one working motorcar in the yard at the time of survey. The numbers of cars driving on unsealed road edges, crossing into yard areas and in some cases driving on unsealed roads within communities is a measure of a potential increase in dust.
In Australia, well over half of the 6,000 houses surveyed (62%) were sited in places that regularly experience temperatures of 40°C or higher. These temperatures usually occur in dry conditions ideally suited to evaporative cooling.
Only 19% of houses had some type of evaporative cooling systems, this has increased since 2013 (+8%). These low energy-using systems use water and air to cool efficiently in hot, dry climates. The combination of mineral salt in local water and the scarcity of water in many remote communities can rule out this form of cooling. Using stored rainwater for evaporative cooling will avoid the problem of high mineral salt in water, allow the units to recycle the water and may make the systems viable. Evaporative cooling, unlike refrigerated air conditioning, pushes large volumes of cool air into the house and the positive pressure generated by this air inside the house reduces the entry of dust.
Wind driven dust can transmit animal and bird droppings with bacteria from the ground to roofs and this may then contaminate the rainwater tank supply. It may be necessary to disinfect the community’s main reticulated water supply, after other treatments, to protect against contamination by dust borne particles.
Dust can also affect the performance of health hardware. For example, solar hot water collection panels will be less effective when covered in dust (44% of houses had a solar powered hot water system); appliances such as washing machines have a shorter life due to the build up of dust in moving control parts; and the function of sliding doors and windows can be affected by dust build up in tracks. In dust prone areas, particular attention needs to be given to the selection of health hardware to ensure it will not fail.
Design and Specification
Ensure
- B7.1.1.
fences are provided to allow the development of yards and reduce dust by encouraging: planting for dust control, limited movement of motor cars near the house, yard taps that can provide irrigation of the yard
- B7.1.2.
concrete, paving or gravel is used near house entrances to reduce dust
- B7.1.3.
at least one of the verandahs or outside living areas is facing away from prevailing, dust-carrying wind
- B7.1.4.
yard areas are covered with ground cover, gravel or mulch, and the surface contours of the yard are shaped to capture, retain and direct rainwater that can be absorbed by plants in the yard
- B7.1.5.
yard taps are provided and located to allow a hose or drip irrigation line to reach all parts of the yard
- B7.1.6.
in areas prone to dust storms, all openings and vents in the house can be secured against dust entering the house
- B7.1.7.
wall to floor junctions are detailed to exclude dust from the house
- B7.1.8.
weather strips are specified for all external doors
- B7.1.9.
window opening and at least 600mm from the ground and can be sealed against dust coming into the house
- B7.1.10.
insect screens are fitted to windows and doors to assist in filtering dust and the screens can easily be removed for cleaning.
Consider
Drip irrigation lines are known to consume large volumes of water because they can be turned on and forgotten; to avoid wasting water fit a timer device between the tap and the irrigation line and check local water restrictions.
Consider:
- raising floor levels to above 1 metre, or a combination of floor and window sill levels to 1 metre above the surrounding natural ground level
- not using timber decking in extremely dusty areas as the dust could blow up from below the deck
- having all window sills at approximately 1 metre above the ground but consider whether this will reduce effective cross ventilation in the tropics, and talk with community members about whether this would change what they can see from the house
- providing low walls, screens or landscaped mounds to verandahs and outside living areas
- using fences, rocks or other barriers, to keep vehicles out of landscaped and unsealed areas
- sealing driveways, parking areas and paths
- building landscaped earth mounds, growing vines on low fences, or planting dense shrubs on the yard perimeter and on the edges of any outside living areas that are exposed to dust carrying winds
- installing rainwater tanks to collect water for watering plants and, if the water is also used for drinking, using a first flush device to divert the first load of polluted water from the roof away from the tank (see B4.1 Quality of Drinking Water)
- ducted evaporative cooling in hot, dry climates as the system will ‘pressurise’ the house and reduce the entry of dust
- installing rainwater tanks, to collect low mineral salt water, for evaporative cooling systems in hot, dry climates
- providing an irrigation system, particularly along the fence line or landscaped mounds, to water trees, fruit and vegetable plants, and create wind breaks with vines inside and outside the yard.
Real world examples of Solutions
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Concrete near house entrances to reduce dust
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Concrete near house entrances to reduce dust
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Reducing road dust
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House yard then a dust catching earth mound, fence with rocks protecting the fence from vehicle damage
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House yard with secure fence excludes feral animals and allows the establishment of dust suppressing plants and food trees.
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In desert areas, local teams build low earth mounds to limit the spread of wind driven dust
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Earth mounds catch low wind driven dust and are stabilised by local seed over time
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Dust monitors placed in key places around a community allow the evaluation of any dust control measures.
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In desert areas, water is scarce, and the earth mounds that stop wind driven dust are stabilised by self seeding local plants
- B7.1.1.
Quality control
- wall to floor junctions are sealed
- AT HANDOVER
FINAL COMPLETION
- AT HANDOVER
- weather strips are fitted on external doors
- COMPLETED DESIGN & SPECIFICATION
AT HANDOVER
FINAL COMPLETION
- COMPLETED DESIGN & SPECIFICATION
- areas around doorways and windows are sealed as specified
- COMPLETED DESIGN & SPECIFICATION
AT HANDOVER
FINAL COMPLETION
- COMPLETED DESIGN & SPECIFICATION
- yard taps and irrigation systems are installed, secured and working
- COMPLETED DESIGN & SPECIFICATION
AT HANDOVER
FINAL COMPLETION
TRADE TEST
- COMPLETED DESIGN & SPECIFICATION
- the yard has been landscaped and planted as specified in the contract, and the plants are alive and well protected to ensure they become established
- SKETCH DESIGN
COMPLETED DESIGN & SPECIFICATION
AT HANDOVER
FINAL COMPLETION
- SKETCH DESIGN
- fencing, if specified, is installed and secure and all gates work
- COMPLETED DESIGN & SPECIFICATION
AT HANDOVER
FINAL COMPLETION
- COMPLETED DESIGN & SPECIFICATION
- rainwater tanks, if specified, are secure and downpipes are connected to the tanks and if the water is to be used for drinking, a first flush device has been fitted
- COMPLETED DESIGN & SPECIFICATION
DURING CONSTRUCTION
AT HANDOVER
FINAL COMPLETION
TRADE TEST
- COMPLETED DESIGN & SPECIFICATION
- the yard's surface has been shaped and graded to direct water to garden areas and prevent erosion.
- COMPLETED DESIGN & SPECIFICATION
DURING CONSTRUCTION
AT HANDOVER
FINAL COMPLETION
- COMPLETED DESIGN & SPECIFICATION
- wall to floor junctions are sealed
Maintenance
As part of cyclical maintenance, check and, where necessary, repair or replace:
- weather strips on doors and seals on windows
- Carpenter, Local Maintenance Team
- 12 Months
- fences and gates
- Carpenter, Local Maintenance Team
- 12 Months
- the condition of yard plants and any surfaces that reduce dust
- Local Maintenance Team
- 12 Months
- the function of taps and irrigation systems
- Plumber, Local Maintenance Team
- 12 Months
- gutters, downpipes and rainwater tanks
- Plumber, Local Maintenance Team
- 12 Months
- clean insect screens to remove dust.
- Local Maintenance Team
- 12 Months
- weather strips on doors and seals on windows
Standard And References
Lansingh, Dr Van C 2005, Primary health care approach to trachoma control in Aboriginal communities in Central Australia. PhD thesis, Ophthalmology, Centre for Eye Research Australia, University of Melbourne
Seidel, M. 2002, Dust control, Bush Tech #14, Centre for Appropriate Technology, Alice Springs
Godjin, Z 2001, Harvesting of Stormwater in Remote Arid Indigenous Communities using examples from Kalka and Piplayatjara in the Anangu Pitjantjatjara Lands South Australia, Rio Tinto/Centre for Appropriate Technology Inc.
Pholeros, P 1991, AP Design Guide, Building for Health on the Anangu Pitjantjatjara Lands, Nganampa Health Council Inc., Alice Springs, pp. 46−7.