- a)Infection transmission: This could be bacterial, viral and other disease causing organisms
- b)Physical bodily injury: These may include cuts, drowning, blunt trauma, and chemical or radiation injury. This may range from immediate skin or inhalation burns, to longer terms effects.
- c)Non-communicable diseases- long term exposure may lead to cellular damage and development of cancer while other might result in bodily organ injury and damage.
- d)Emotional/psychological effects (strong smells, unsightly waste as human body parts)
One type of solid waste may lead to more than one health outcome directly or through an intermediate mechanism for example through vectors and other individual level predisposing factors.
Poorly managed medical waste, is a major source of infection for patients, health care workers, waste handlers and general public [, , ]. Where all medical waste is properly disposed of, the risk of infection to the general public is limited, but remains substantial to providers and their clients. While protocols on handling medical waste exist in many settings, their implementation varies from one place to another depending on how stringently prevention of infection protocols are implemented and observed. Indeed many health care personnel and medical waste handlers do not use personal protective gear [, , , ].
A variety of pathogenic organisms are transmitted from biological specimen, contaminated medical waste and sharp medical objects such as hypodermic needles. Hepatitis B infection is a common infection often transmitted through skin cuts, mucous membranes, needles stick injures and contaminated surfaces [, , ]. Although it is recommended that all used and disposable sharp equipment should be discarded in a sharps containers, these are often not available resulting into many health personnel getting needle stick injuries. The risk of transmission of infection from medical waste is substantial including hepatitis B, ebola and Hepatitis C among others [, ]. Other important pathogens that can be transmitted from medical waste include pathogenic bacteria such one that causes tuberculosis, anthrax, pneumonia, meningitis, and infections of the gastro-intestinal system. Evidence shows that workers who handle medical waste are at a higher risk of nosocomial infections [, ].
Decomposing organic waste is a rich medium or culture for growth of numerous micro-organisms many of which are diseases causing if passed on to humans. Also there is always a risk of transmission through vectors such as houseflies but also through human contacts as is the case with waste handlers who do not use protective wear and waste pickers who most of the time use bare hands [, , ]. Additionally, articles retrieved from waste may be sold to unsuspecting public without undergoing thorough cleaning hence posing a risk of infection transmission.
Gastro-intestinal infections such as typhoid fever, polio virus infection, hepatitis E infection, and cholera are often transmitted through contaminated food or water [, , ]. Toilet ownership in Kenya, for example, is very low with 12% of all households not having any form of toilet . Even those households with a toilet, many are not connected to the main sewer line. These result into fecal matter being disposed of in open spaces while other households do not have any form of toilet and thus dispose of fecal matter as general waste, popularly referred to as flying toilets or discharged into rivers . Human fecal matter is a known source for pathogenic enteric parasites, typhoid fever infection, polio virus infection, hepatitis E infection, cholera and common gastroenteritis transmitted human contact, vectors or contaminated water . Studies have revealed high levels of pathogenic parasites in dump site waste confirming the risk waste handlers and pickers are exposed to . This challenge of proper feacal matter management is not limited to households but also institutions such as hospitals and schools. There are reports of cholera outbreaks emanating from fecal waste coming from a hospital [, ].
In many developing countries, the practice of sorting waste at source is almost non-existent even for high risk waste such as sharps generated from medical facilities [, ]. Presence of sharp objects in waste poses a high risk of injury to both those who generate the waste, the handlers and pickers [, , ]. Poorly disposed surgical blades, needles frequently injure medical workers, medical housekeepers and waste collectors of medical waste while sharp objects such broken glass injure domestic workers and waste handlers. Where waste is disposed of in open dump site accessible to pickers, the risk of injury from sharp objects is ever present .
Urban floods are common in many cities. While poor urban physical planning may be largely to blame for the increasing phenomenon of urban floods, partly the problem can be attributed to rampant blockage of drainage systems by solid waste [–]. Inappropriate disposal of waste, especially the non-biodegradable plastic paper bags results into these being swept downstream resulting into blockage of drainage systems. Floods not only destroy property, they have claimed lives both on roads and homes and damage sewerage systems leading to wide spread environmental contamination with human waste and associated risk of infection transmission [, ]. Blocked drainage systems are also breeding sites for diseases transmitting vectors such as mosquitoes.
Injuries from chemicals can be in the forms of skin burns, inhalation burns, explosions and intoxication. Fumes from burning chemicals at dump sites or from incinerators may cause respiratory, allergic and other complications [, ]. Pharmaceutical and industrial chemicals are often not disposed of appropriately and at times get back into the market. Obsolete pesticides, old batteries, among others contain chemicals that are dangerous to human life yet are often disposed of just like common litter . Medical waste may also include substances that are cytotoxic and or carcinogenic. Improperly disposed substances and equipment may result is disastrous effects to the public as was the case with the caesium-137 irradiation accident from a disused radiotherapy unit in Goiania, Brazil .