Thursday, April 16, 2015

Plastic and Waste Management in the Context of Sustainable Building

Ellie Hayden and Pat Wendler
Problem: There is Plastic everywhere due to a lack of waste management in Senegal


Introduction:
One of the problems we identified while in Senegal was their lack of waste management. While high volumes of trash is not unusual for a large city, there are usually several receptacles and a system that prevents trash buildup. However, in the few days we spent walking around Dakar, not once did we see a trash can along the streets. Instead trash was just thrown on the streets. Even locating trash cans in buildings was often difficult. Although we did not witness the system in action, from our interviews, we understand that there is a waste management system, but it is not very well organized. Instead of leaving trash outside to be picked up, it seems that a truck simply drives down your road once a week and if you’re there to throw your trash in the truck as it drives by, great, but if not, you’re out of luck and that week’s trash is usually improperly disposed of.
As you get further from the city, trash becomes even more of an issue as there is a lack of infrastructure and less incentive to support any kind of formal system for dealing with waste. This results in high volumes of trash in the streets especially just outside the entrances to rural villages. The one form of waste management we identified in the rural areas stems from a social movement called “Set/Setal” meaning be clean/make clean. This is a movement that began around 1990 and was encouraged by a popular musician at the time whose hit song encouraged the youth to keep the streets clean. To this day, young women and men take time off from school to clean the streets and burn the trash piles. We witnessed this in Keur Momar Sarr and while this movement stems from good intentions, it causes even more problems for their health, the environment, the economy, and the society as a whole. To fully understand the depth of this problem, we have explored the root causes as well as the implications that have arose from it. Using that and the other information we gathered on our trip, we have come up with a few ideas of how we could approach this problem in a way that could advance sustainable building in Senegal.

DSC_5321.JPGDSC_5554-001.jpgDSC_5573-001.jpgDSC_5574-001.jpgDSC_5594-001.jpgDSC_5635-001.jpg

Analysis:
After thoroughly exploring this issue, we came up with some questions we thought were important for moving forward.
  • What challenges are worth trying to solve?
  • How can solving part of the waste management challenge help with sustainable building?
    • How can we think of the issue in the context of sustainable building?
  • What differences exist between rural and urban waste management?
  • How rapidly is Senegal urbanizing, and how will this affect waste management?
  • What incentive for waste management would matter to the Senegalese?
    • What consequence would be meaningful to them?
  • Can we use trash for building? What effect would it have? Would it be sustainable?
  • What’s being done currently to solve the waste management problem?


The main problems that arise from the current waste management (burning trash piles in the villages) are degradation of health and the environment. Having spent some time with several Senegalese families, I think the best way to create incentive for them to want to change their waste disposal methods would be to approach it from the health point of view. If we can help them understand that they are potentially making themselves, their children, and their loved ones sick by burning the plastic, I think we will have a better chance at getting them on board.



Health facts:
  • Burning plastic releases dioxins and furans which are linked to cancer and respiratory diseases (dioxin comes from high chlorine amounts).
  • Inhaled smoke from plastic can cause hormonal imbalance.
  • The ash is potentially hazardous to soil.
  • Dioxins can enter the food chain by settling out of the air and into water and vegetation that is then consumed by humans or animals.
  • Dioxins can suppress immune system making people more susceptible to other sickness, disease, or infection.
  • Particle pollution from burning plastic can cause respiratory problems, irregular heartbeat, and heart attack if the particles settle in lungs.
  • The effects of burning plastic will be felt by the youth and elderly most.
  • Lower respiratory infections are responsible for 8.4 years of life lost (YLLs) in Senegal.
  • Lower respiratory infections are the third greatest cause of premature death in the country.
  • Garbage piles are breeding grounds for disease and also attract animals that go on to spread the disease


Environmental Facts
  • Littering kills wildlife.
  • Wildfires can start from a spark or lit cigarette igniting a garbage pile - especially in dry conditions.
  • Toxins from garbage piles can seep into the groundwater, which makes its way to water systems or plants.
  • Garbage by bodies of water can cause algal blooms, which pollute freshwater sources and kill freshwater wildlife by leaching oxygen from the water and creating an unbalanced ecosystem.
  • Plants and animals that don’t die from ingesting toxins from garbage are poisoned, and some of these poisoned plants and animals are eaten by humans.
  • Burning garbage releases nitrogen oxides, volatile organic compounds, carbon monoxide, and particulate matter, which contribute to ruining a region’s air quality and polluting the atmosphere, which worsens global warming and climate change.


Moving Forward:
How can we approach this issue in a way that can apply to sustainable building in Senegal?
Potential Ideas:
  • Plastic as an aggregate used in concrete used for building
  • Plastic as an insulator for buildings


Research pertaining to future ideas:
In depth study of using plastic bags as aggregate for concrete in Nigeria:
  • file:///Users/Ellie/Downloads/Evaluation%20of%20suitability%20of%20LDPE%20as%20fine%20aggregate%20in%20Concrete.pdf
    • A plausible idea, but would work best for non-weight bearing structures, like tiles for partitions or maybe tiles for the roof


Plastic bags used as an aggregate for pavement in Mauritius and India


Recycled plastic bottles as an insulator in building:


Potentially useful facts about plastic bags:

  • plastic bags are made out of low density polyethylene (DLPE)
  • tensile strength 8-30 MPa
  • 100-650% elongation at break
  • flexural modulus .25-.35 GPa
  • density: .92-.93 g/cm^3
  • moderate degree of crystallinity
  • crystal melting temp = 110 C
  • 20-1000 years to decompose
  • “A copolymer of ethylene with some carbon monoxide contains ketone groups that absorb sufficient energy from sunlight to cause extensive scissioning of the polymer chain. The photodegradable plastic, very similar in appearance and properties to low-density polyethylene (LDPE), decomposes to a powder within a few months of exposure in sunny climates.”

The Factors of Ventilation

Factors contributing to the construction of Homes in Senegal
Documentation

  1. Auberge

This location shows how the environment is taken into consideration where wind and natural light is used from the outside. This is a relaxing area where no extra energy such as light or air conditioning is usually needed due to the use of the space.


IMG_2608.jpg

The way this location in the Auberge uses the courtyard is a really great way where it takes into consideration all the natural light provided by the sun and has shade through the use of vegetation.
This is an example of the type of windows currently used where the slant in the windows allows for natural light and wind circulation to occur. This type of design however does not allow for them to be closed and let mosquitos and other bugs in.
This is showing another view of the upstairs lounge area in the hotel where the space is clearly meant to resemble the same purpose as courtyards do, a place to socialize and relax during the day.

2. Sacree Coeur
IMAG1678.jpg
This is an example of a recent neighborhood development in Sacree Coeur where middle class homes are being developed and are taken environmental aspects into consideration. This includes better air circulation through the different designs for the windows, doors, and outside elevations. The second story shows a incorporated porch design which helps with ventilation.


This picture shows one of the temporary homes being built all around Dakar so that land can claimed. These homes provide many jobs but are not efficient material-wise as these homes get destroyed after they are approved and are usually replaced with the homes in the previous page.














3. Thiaroye Sur Mer

IMAG1733.jpg
Location: Thiaroye Sur Mer.
It is one of the poorest neighborhoods of Dakar. The houses are built right next to each other and a small alley separates block of houses. The doors and windows have small openings to let the air in.

4. Keur Momar Sarr
IMG_2726.jpg
This shows an upclose view of a window style where air circulation is being taken into consideration and is a cheap and affordable alternative to a window with glass.

temp in mens room 4 pm Mar 12.jpg

This temperature reading was taken from one of the bedrooms in Keur Momar Sarr and shows how hot it can get and the current temperature at that moment. It reached a peak of 84 degrees Fahrenheit and was currently that temperature when this picture was taken in the afternoon around 3 pm.




This is showing the temperature inside of a school room in Keur Momar Sarr where as can be seen, can get really hot but with low humidity.


Analysis

  1. Doors
As can be observed through the pictures above, some people would rather have air circulation than safety from mosquitos and malaria as temperatures can get really high, especially within a confined space. Doors would best be made from wood since it has a lower heat coefficient than most materials used for doors. Metal doors have a heat coefficient of 1.2 Btu/hr ft^2 degrees Fahrenheit while wood can either be .45 or .65 Btu/hr ft^2 degrees Fahrenheit.

  1. Roof
The roof is a very important aspect within the construction of homes and buildings and does not seem to be as high in priority. Roofs can have a major impact on the temperature within a home. A high solar reflectance is the most important characteristic of a cool roof as it helps to reflect sunlight and heat away from a building, reducing roof temperatures. A high thermal emittance also plays a role, particularly in climates, like in Senegal, that are warm and sunny. Reduced energy use makes a cool roof transfers less heat to the building below, so the building stays cooler and uses less energy for air conditioning. Roofs can also Improve human health and comfort as cool roofs can help to prevent heat-related illnesses and deaths. Together, these properties help roofs to absorb less heat where this can have an impact on the lifestyle of its inhabitants.
Chimney (stairs)
Although chimneys are not too common, chimneys can affect air circulation quite well in favor of the homeowner. Roofs create the stack effect which will cause air circulation. During the hot season, the warmer indoor air rises up through the building and escapes at the top either through open windows and ventilation openings. Since warm air is rising, it reduces the pressure in the base of the building where cooler air can come in through windows. One way that can create this stack effect is through staircases as was the case where we spent our nights in Keur Momar Sarr. This style allows for air circulation without interfering much with the homeowner’s lifestyle.
image from:

  1. Sun directions
After several interviews with masons and homeowners, the findings about the sun direction was the same, it was not taken into consideration in the design and construction of buildings. However, knowing the direction of the sun is critical while building a house, especially when it comes to the openings and ventilation. Knowing the positions of the sun at each time of the day enables the architect to design accordingly. For example, facades on a house to provide shades for the building and help with overheating.
Definitions


  1. Wind Directions
Another important aspect to consider when designing a building is the wind directions, especially in countries that are affected by high wind currents. Surprisingly, there were little to none consideration to wind directions in building designs and constructions in the places visited in Senegal. Even though people knew the wind direction, this critical information was ignored.
In the school in Keur Momar Sarr where we visited, the buildings were built against the wind directions. Therefore, the rooms temperature were very high  and the air did not circulate easily.
By knowing the wind direction, architects can provide openings to ease the ventilation inside the buildings. In a classroom in Louga, the windows were built to facilitate the ventilation inside, making the room very comfortable.
           
  1. Property of Materials
For roofs, one of the most commonly used materials is corrugated metal. Corrugated metal is available in sheets with wavy ridges and is used in construction projects for roofing or siding. It is lightweight and economical to install and is highly durable and is able to support a large amount of weight without buckling. Homes in coastal regions are more likely to use corrugated metal, since it is a moisture-resistant material. It is a low-maintenance choice, and may be less expensive to install than other building materials, such as brick or concrete. This product can also be recycled, and this fact makes it attractive to homeowners who want to go "green." Corrugated metal siding can be made from aluminum or steel. Aluminum is the material of choice in areas near the ocean, since the aluminum will react with the moist, salty air to form aluminum oxide.
When looking at heat transfer coefficients, corrugated metal as a roofing material is 1.5 Btu/hr ft^2 degrees Fahrenheit while 2 inches of concrete slab has a coefficient of 0.3 Btu/hr ft^2 degrees Fahrenheit. As can be seen, concrete would be preferable as it has a lower heat coefficient.
Tile roofing, which lasts a long time and will not burn under a scorching summer sun, is a great choice for warm climates. Clay tile, which was used in one of the schoolhouses, usually last longer than any other kind of roofing material. Tiles are also fireproof and resist rot and insects. These tiles are however very heavy that the roof needs reinforcement to support its weight. Concrete tiles will last just about forever but the the material they lie on will go bad every eight to twenty years. Tile roofing is also expensive which explains why it is not used as often.

  1. Challenges with Ventilation
Even though ventilation is an important aspect to consider in building construction, there are some challenges associated with ventilation, especially in the country of senegal.
    1. Insects and Diseases
By letting too much air in, there is a risk of letting insects inside the house, especially mosquitoes. Most houses are build with a central open courtyard. The courtyard helps with the ventilation, however, it allows mosquitoes to get in and spread malaria. In the raining season, malaria cases may increase due the the high number of mosquitoes. In the dry season, there are a lot of flies that spread diseases such as typhoid fever, cholera and dysentery.  

malaria.JPG

    1. Energy costs
The lack of proper ventilation causes many Senegalese families to invest in fans or air conditioners, which drive their electricity cost very high. In an interview with Aminata, a jewelry seller on the Island of Goree, she revealed that she spent about 20,000 F CFA, an equivalent of $40 on electricity each month. Her energy bills represent a big portion of her volatile income. The reason why her energy cost is so high is the fact that her one room house does not have the proper ventilation to provide a comfortable and cool environment.

    1. Dust
Because of the dry and arid climate, dust is a threat to many households. Therefore, without proper ventilation techniques, the wind can spread large amount of dust inside buildings, making inhabitants lives very difficult. In the recent years, the numbers of dust storms has increased because of climate change.
Senegal dust storm

image from http://newscenter.berkeley.edu/2011/12/12/climate-change-kills-trees-in-africa/

Wednesday, April 15, 2015

Malaria, Bugs & the Outside World

Malaria, Bugs & the Outside World
by Talia Dunyak & Jennifer Chen


  1. Data
  1. Clinics: The clinics in Senegal are generally run by doctors. They are often in charge of distributing bed nets and giving vaccinations and other medical tests and treatments. Sometimes clinics are too far away for people to easily access. They’re are not enough doctors within Senegal because of the “brain drain.”
  2. Bed nets are usually hung from the ceiling or wall and should cover the entire bed. There should be one net for each bed, but due to the lack of nets this is not always the case. Nets come in several varieties and can be changed from circle to square nets and vice versa.
  3. Nets should be washed with regular soap and water and not with detergent. They should be air dried in the shade, not in the sun. This helps to make the impregnation last longer.
  4. Bed nets are shipped to Senegal from other countries. Some labs are dedicated to testing the efficiency of the nets (making sure they last as long as the company says they do).
  5. Bed nets are freely distributed through the Senegalese governmental organization PNLP every five years. This allows many people to receive nets and because of this the malaria rate has gone down.
  6. Mosquitos are attracted to standing pools of water and breed in stagnant water. Because people often wash their clothing in the courtyards of their homes, standing water can be a problem within homes.
  7. One way to prevent mosquitos coming into the home is by using screens. The problems with screens is that they often allow for dust to blow into the home, which is undesirable.
  8. After malaria, typhoid is the most common disease. Typhoid is spread by dirty water and food and can spread quickly throughout a community.
  9. A new lab will be opening soon in Thies. It was funded by Tulane University and will be used for  laboratory research. This Lab is connected to the existing lab that does work with testing the effectiveness of nets.
  10. Although nets are not always free, free nets should be given to pregnant women by clinics. Pregnant women should also take several pills as a precautionary effort against malaria.
  11. Many people are in health associations, which work sort of like insurance groups. By paying a nominal fee, members are granted access to free or subsidized healthcare and transportation to clinics.
  12. The best protection against malaria is sleeping under bed nets.
  13. Bed nets are also the cheapest form of protection against malaria, and nets when not free only cost about 500 CFA ($1).
  14. Educational campaigns, such as the ones held by Speak Up Africa, have helped to lower the prevalence of malaria in Senegal.
  15. “Set setal”, the cleaning of the village streets to prevent trash buildup, which may attract mosquitos, flies, other bugs, etc.

  1. Analysis

  1. The only time you are under the bed net is when you’re in bed, so during the day, there are still many opportunities to contract malaria. Ways to work around this problem include finding alternative ways to preventing malaria.
  2. One problem is that in rural areas, clinics can be few and far between and there may not be any available doctors. This is because of the brain drain currently occurring with Senegal’s professional class, who are using their Senegalese education to go elsewhere. Even if doctors are available, transportation to the doctor is an issue as well.
  3. Bug spray is also good protection (used by foreigners) but it is not readily available for local communities - too expensive. Regarding the environment it might not be environmentally safe to use sprays, but it could help.
  4. In outdoor courtyards, if it was possible to either put some sort of net or screen over the “roof” of the courtyard, this could greatly reduce the amount of mosquitoes present in the outdoor living space. For cooking, some sort of chimney structure could be created to let smoke out.
  5. The development of an insect-repellent brick or paint could be developed to help ward off mosquitos from the home.
  6. Because mosquitoes are attracted to standing water, there has to be a way to reduce (or reuse?) standing water. Ways of doing this could involve planting gardens in the courtyard that use the drain water from bathing/cooking or finding some sort of way to drain and reuse water so it is not standing in the outdoor living space.
  7. Regarding the standing water, on a national infrastructure based way, a movement to create drainage systems could help with the removal of breeding grounds of mosquitoes. (see article)
  8. It could be possible to make some sort of nets or screens out of recycled plastic. This would both reduce trash and work to increase screen usage in homes.
  9. Why are window screens not a main method to keep mosquitoes out of homes? Window screens are fairly cheap and sturdy, and they can be nailed to the window or wall. Yes, dust will still get into the house, but dust will get in through any open window or door. Drapes and other coverings could also be used to decrease dust, if it’s a concern.
  10. Children are the main targets of educational campaigns. Schools are a good target to reach the major audience. To get children engaged, many campaigns use sport platforms, such as soccer. Educational campaigns are proven to be effective in the fight against malaria.
  11. One major thing that could be done is figuring out a type of screen that could be made or incorporated into buildings. If we are considering making bricks with slits (weep holes) in them, maybe it would be possible to build a brick that has a built in screen. It could work as both an aggregate and a way to eliminate mosquitoes entering the home.
  12. When some people notice the symptoms of a disease, they may automatically assume it’s malaria because it’s so prevalent (malaria and typhoid also have very similar symptoms) Doctors will give them medication without doing any lab tests to confirm that the person has malaria. If they don’t actually have malaria, it is a waste of resources to distribute the wrong medication, and could also be a cause of death.