Impact of disaster on public health – Pt 2

by: Reynold Hewitt Tue, Aug 10, 2010

Earthquakes

Earthquakes can cause a large number of injuries. Injuries and fatalities resulting from earthquakes vary from event to event and place to place. The extent of the injuries and fatalities relate to intensity of the earthquake, population density, strength of the buildings, and the time of day.{{more}} While there are large numbers of factors associated with the impact of earthquakes on human lives, a key factor associated with fatal injuries in earthquake is the collapse of buildings. In Haiti, most of the injuries resulted from building collapse resulting in thousands of deaths. This is related to the magnitude of the earthquake, its proximity to populations and buildings, soil conditions and construction practices. Many of the buildings collapsed because building codes were not followed; buildings were constructed without steel and the correct concrete mixture.

A small earthquake can have devastating effects. In Colombia a 5.9 magnitude earthquake occurred in an agricultural area where the soil condition exacerbated the shaking. The construction practices prevalent in buildings in the region did not include any codes for anti-sesmic reinforcement. As a result of the earthquake, hundreds of reinforced concrete building collapsed, killing nearly one out of every 250 people in this community of 250,000. The force of the earthquake is not the only cause of death. Secondary hazards such as firestorms and Tsunamis can reap havoc and result in a high death toll. In a Kobe earthquake, an estimated 10% of the deaths were as a result of ruptured gas lines. The rubble in the narrow streets restricted the fire department’s access to the fire, allowing the fire to spread across large sections of the city.

Earthquakes can also cause tsunamis resulting in a large number of deaths. This may happen since the water hits with a force that is unstoppable, and some persons may die from the impact or die because they are unable to swim.

In 1998, a magnitude 7.0 earthquake struck off the coast of Papua New Guinea. While the quake was felt, it did no damage to the small houses in the villages off the coast. However 15 minutes later, three tsunamis struck the coast villages killing an estimated 3000 of its inhabitants of the region. The waves exceeded 12 meters. Many of these deaths were a result of the force of such a large amount of water surging against the body. Some people survived but later died because they were unable to swim.

Communicable Disease

Many believe that the primary role of public health in disasters is to control potential communicable diseases which may outbreak after a disaster. While it is true that the potential for outbreaks and even epidemics of infectious disease exist after any natural disaster, the actual occurrence of such outbreaks is rare. In order for the risk of epidemics to exist, the disease must exist in the population prior to the disaster.

The risk for the incidence of infectious diseases increases due to deteriorated hygiene and overcrowding, within several days after a disaster. Thereafter, depending on the level of hygiene at the refugee camp, the risk for various infections has been shown to increase. The most common types of infections observed in refugee camps include diarrhea, acute respiratory infection (ARI), measles, and malaria, which are called the four major killers. In addition, increases have been reported in various infections, such as the epidemic of tuberculosis due to crowded living conditions, tetanus arising from unsanitary treatment of injury and childbirth, various parasitic infections, and scabies due to the shortage of water.

Hurricanes

The Caribbean region is located in the Caribbean belt, which is known for some of the most dangerous hurricanes. Although we have improved the technology used in tracking hurricanes, the fatalities still occur. The impacts of hurricanes are often strong winds, heavy rains that damage buildings, land slippage that claims lives and injuries that are life threatening.

In reality, although humans can do little about the causes of weather events, humans have been increasingly able to reduce the impact of weather events on society. Early warning systems can alert costal populations of approaching tsunamis and they can give populations time to be evacuated from danger areas.

In October 1999, Hurricane Mitch devastated Central America. Even though the hurricane had been tracked, warnings were not issued to the population. The pattern of injuries and deaths associated with Hurricane Mitch was also different from other hurricanes. Generally hurricane related mortality has principally been associated with drowning from storm surges. But a large number of Hurricane Mitch fatalities were associated with inland flooding and mudflows, resulting from five days of torrential storms leaving behind 30 inches of rain.

Hurricane Ivan impacted Grenada causing 13 deaths. The hurricane had sustained winds and gusts which damaged 90% of houses and destroyed 30% of them. Every major building in the city was either damaged or destroyed. Ivan’s passage either damaged or destroyed 85% of the infrastructure on the island including the nation’s emergency operations centre. An estimated 18,000 people were left homeless and 700 people sustained injuries from the storm.