Ventilation in the slums: A Game of Cat and Mouse?

(Photo: The Cat in the Rat Strikes Back: While most cats in the Zabaleen community have learned (through painful experience?) to ignore or run away from rats, this frisky young fellow, under Adham Fawzi's bed, has proved his worth to the family by nabbing a would-be intruder. One of Solar CITIES coordinator Hana Fathy's relatives recently lost a newborn baby daughter to rats that invaded her crib and ate through her delicate head -- a tragic and frightening prospect for any young family.)

Because of the persistent rat threat in the Zabaleen community, many families are forced to board up windows and other openings, making their homes' air quality, in terms of smoke, carbon monoxide, off-gassed pollutants from synthetics and airborne disease organisms, health hazardous. The trade off is of vital concern to residents, but the cost of glass windows and fitting window frames, of well fitting doors and the cost of finishing walls is so high that families are forced to simply board things up.

Given that people must cook and heat water on gas stoves indoors, the urgency of providing flame-free heating systems is manifest. Since solar hot water systems involve no burning of any fuel they are ideal for families in rat-infested communities. Their price however, even when home-built, is prohibitive (roughly 2,500 LE, or $500) for families earning as little as 400 LE (20 dollars) per month.

Another solution is electric water heating, applicable where the electric infrastructure is safe enough to support the heavy load (electric heaters can consume between 1500 and 4000 watts, depending on design). In the informal housing sector electric wiring is often substandard and dangerous; most houses in Cairo in general are completely ungrounded, and the combination of wall mounted electric water heaters, damp walls, wet concrete floors and flowing shower water is a deadly mix. Many families speak of receiving shocks and of knowing people who have been electrocuted in the shower. Other families, however, consider electric heaters safer than gas heaters.

Certainly electric heating has no adverse effect on indoor air quality. It would thus seem well suited for families in rat infested areas where bathroom and kitchen windows need to be boarded up.

Could uncertain income explain why so few people use them?

Electric heating, preferred by only 54.5% of the surveyed population in Darb El Ahmar, and only 28.4% of the Zurayib Zabaleen, may be too expensive for people whose incomes are uncertain.

In our survey 60% of the Zabaleen have uncertain monthly incomes, and 55% of the craftspeople of Darb El Ahmar have no way of knowing how much they will bring in at the end of every month.


Does this correlate with possession of an electric hot water heater? First of all, let us look at the aggregate data, without considering household correlations. In the case of the Zabaleen, it does seem as if income uncertainty/certainty has some explanatory value in predicting disuse/use of electric hot water heaters:

It is less clear, however, if this "cue" discriminates in the case of the Darb El Ahmar community, and can thus be used as a basis for an inference. In Darb El Ahmar only 40% of the people have certain incomes, yet 54.5% use electric heaters. We have not yet run the statistical tests to see if this is significant.





Still, the argument from income uncertainty is compelling: All of the families in our samples depend on electricity for lighting, refrigeration and fans, and since a third of electricity demand can be consumed by grossly inefficient "resistance heating" appliances (i.e. appliances that use the heat generated by metal coils when high current electrons are forced through them), most families are afraid of high electric bills whose non-payment could result in a total suspension of service. In other words, overuse of an electric heater could result not only in the electricity to the heating appliance being cut, but to electricity being cut to the whole household! They would thus prefer not to use electric heaters and guarentee that they can pay their monthly bills and keep the lights on.

And in an a dank, dark apartment without windows or ventilation, keeping the lights on is of paramount importance, to say nothing of being able to use a fan...

How extant is the lack of ventilation? It is hard to tell from our data. Our survey contained the question "is there ventilation is the bathroom (yes/no)" and "is there ventilation in the kitchen (yes/no). " The problem is that the Arabic literally reads ,"are there openings for air" ("fatHat Al Tahweya"). When I went into homes that I knew had boarded up windows and conducted the survey myself, the respondents said "yes" to both questions, even though I could see (in the dim half light of the naked bulb hanging in the adjacent room) that the openings were sealed. In one such house, that of my friend Moussa, he said, "well, we have the openings, and we intend one day to put proper windows in." "And when do you intend to do that?" I asked. The reply: "When we have money, maybe in a year or two..."
This is typical for incremental housing situations.
Such homes would be listed as "having ventilation -- meaning that in construction a "manwar" or "light well" was provided, and an opening in the bare brick wall was left. But functionally these homes are not ventilated.

The survey, however, which was conducted by a team of three people in Darb El Ahmar and a team of 6 people in Zurayib, who went through the 9 pages of questions like a checklist, only captures those households that specifically stated they have no ventilation.

The data reveals the following:

Zarayib:

Darb El Ahmar:

Clearly the Zabaleen, in the rat infested garbage collection area of the city, have worse ventilation, with 16% of our sample (N = 225) having no bathroom ventilation and 15% having no kitchen ventilation. Darb El Ahmar fares better with 5% of the sample (N = 231) having no bathroom ventilation and 10% of kitchens having no ventilation. Of course, Darb El Ahmar doesn't have the same problem with rats.

History of ventilation among the urban poor:

In urban environments proper ventilation can be a matter of life and death.

For a good history of ventilation see Chapter 2 of the Indoor Air Quality Handbook

By John D. Spengler, Jonathan M. Samet, John F. McCarthy



Written by the Harvard Graduate School of Design's Dr. D. Michelle Addington, the chapter explores ventilation concepts and laws from the first century B.C. to the present, and relates how carbon monoxide from heating fuels caused many deaths in homes without ventilation until building codes mandated vents. You can find excerpts from it here.

Unfortunately, as was brutally pointed out last month when another apartment building in Egypt collapsed, killing the residents, Egyptian buildings rarely if ever are built to code standards. This is true of formal areas (the collapsed building was in relatively upscale Alexandria) but is particularly true in informal communities. This same lack of code construction, however, also makes smoke-free electric heaters a lethal possibility; many people tell stories of knowing people who died by electrocution in the shower, though we have no data suggesting the frequency of such an occurrence.

A very interesting blog entry on urbanplanningtheory.blogspot.com reviews a book called
Housing in Urban Britain, 1780-1914 and contains the following summary:

"Why did slums and suburbs develop simultaneously? Were class antagonisms to blame? Why did the Victorians believe there was a housing problem? The history of housing between 1780 and 1914 encapsulates many problems associated with the transition from a largely rural to an overwhelmingly urban nation, whose unprecedented pace imposed immense tensions within society. This book reviews the recent arguments and guides the student of social history to further reading, making it an ideal introduction to a central issue in nineteenth-century history".


The book may as well have been written about the history of Cairo housing between 1960 and the present, during which time it has had to deal with "the many problems associated with the transition from a largely rural to an overwhelmingly urban nation"; as was well presented in Roh El Shabab director Ezzat Naeem Guindy's theatrical play on the history of the Zabaleen (in which Adham Fawzy and his sister starred) these "immense tensions" have characterized the lives of the dwellers of the Zurayib community since the Zabaleen began arriving there half a century ago.

The book contains a passage from 1869 (on Page 32) describing the high death rate of the English slums that could be applied to Cairo today : "the rate of mortality depends upon the efficiency of the ventilation".