Dr Parvez M Dar and Dr Abhinav Mani
The earth’s crust is divided into seven major and many minor tectonic plates that continuously move over the earth’s interior. These moving plates sometimes suddenly move against each other and the rocks within the earth’s surface break and release a tremendous amount of energy that leads to wave formation called seismic waves. These waves are responsible for the violent shaking of the earth and the phenomenon is known as an earthquake. It occurs suddenly without any warnings and very rapidly, causing violent movements of the earth and everything above it.
Earthquakes are among the most stunning geological processes. These are one of the most unpredictable natural disasters, with the potential to cause destructive effects on human lives and infrastructure. India is very vulnerable to earthquakes and about 58 per cent of the total land in our country is prone to moderate to severe-intensity earthquakes. The country’s seismic zoning map divided the entire territory into four seismic zones. Seismically zone V is the most active region while zone II is the least active. Approximately 10% area ofour country falls under zone V, 18% under zone IV, 30% under zone III and the rest of the land falls under zone II. Areas under the seismic zone V have the highest risk of earthquakes of intensity of magnitude of 9 or more. The parts of India which fall under this zone include states along the Himalayan range i.e., parts of Jammu and Kashmir, Himachal Pradesh, Bihar and the states of the northeast region. The islands of Andaman and Nicobar and part of Gujrat also fall under seismic zone V (Fig. 1).
Safety precautions at the time of earthquake
Preparation before an earthquake: Every person should choose a safe place inside the house and pinpoint them beforehand. The safe places inside the house are the inner wall of the room, corners, under the beams, inner door lentils, and the inner strong core of the building like a lift well area away from windows. Regularly practicethe “drop, cover, and hold on technique”as shown in figure 2.Frequent practices always help to reinforce safe behaviour. Many people hesitate to try to remember what they are supposed to do at the time of the earthquake. Always keep the basic disaster supply kits and emergency supply kits at your home. These kits include a First aid kit, fire extinguishers, battery-powered radio, fresh water and some food, a flashlight or torch, sleeping bags or blankets.
During an earthquake: Despite so many technologies and inventions no one can predict theexact timing of the next earthquake. However, because of recent advances, we are aware now that in which seismic zone we fall and thus we can better be prepared and educated about the probabilities of earthquakes in our area and prepare ourselves for better survival. Public awareness and public education about earthquakes are key to survival. We should not panic, always remain calm and follow the instructions of the government authorities. During an earthquake,if we are inside a building,stay inside, adopt the “drop, cover, and hold on technique”, and stay ina safe place inside the house.Take care of falling objects and shield your head and face with a blanket pillow or box and don’t rush outside. When you are told to leave the building, use the stairs only and never rush as this may harm you.Never use the lifts as the power supply of lifts may go off and you may get trapped inside the lift.Leave your floor only in case of an emergency like fire and always 
make a plan from where to exit safely.
When you are outside, stay there and don’t rush inside the house. Stay away from tall buildings, malls,electric poles and power cables. Proceed cautiously toward the open area. If you are in a vehicle, stop your vehicle at a safe place, not near tall buildings, malls or under the powercablesor electric poles. Stay inside your car and keep the doors of the car closed, don’t open them even if electric lines have fallen on the ground and never come outside as your car is insulated and will protect you from electric shocks because of rubber tires.
Post-earthquake
Immediate precautions: Remain calm and don’t panic and console others also. Don’t go outside until the earthquake has stopped. Don’t light any fire e.g. matchbox, lighter or cigarette. Do not turnon theelectrical switches, instead,a battery-operated flashlight or torch should be used. Try to protect your head and face while moving with a helmet, blanket, or pillow if available. Take a quick survey of your injuries of yourself as well as the family members so that you can give first Aid treatment. Never try to pull seriously injured persons unless there is an emergency like a fire. Doing so can further harm the person instead of helping them. Switch off all electrical appliances and machines and shut off the main switch if possible.Make immediate provision of clean drinking water by collecting some covered utensils as the water supply may go off because of pipeline damage and it may also get contaminated by dust and debris.
Precautions after an earthquake have stopped: Always keep in mind that a second or third earthquake can happen in the form of aftershocks. Take complete access to trapped family members and immediate neighbours especially people of extremes of age and bedriddenpeople. There isalways the possibility of landslides in hilly areas, tsunamis in coastal areas or fire. Keep the radio on to get necessary information and instructions from the government authorities.Use telephones only in case of emergencies to keepphone lines free for other needy people.Inspect gas pipes for any damagebefore use and if possible, try to avoid using flammable material. Check if sewage pipesbefore using the toilet to preventthe spread of infections.Don’t try to go inside houses unnecessarily or until the authorities declareit to be safe. Do not roam outside unnecessarily. It may cause hindrances in the ongoing rescue work.
The outbreak of infectious diseases post-earthquake: Infectious diseases emerge following any disaster. Thus, the survivors of earthquakes are at high risk to get these infectious diseases. These diseases are categorised as water-borne, air-borne or vector-borne diseases and contamination of the external wounds. Infectious diseases mostly occur during the post-impact phase of the earthquake, which usually lasts from 4 days to several weeks. During this phase, both the newly appeared infections and those that are endemic in the particular area could spread and turn into an epidemic. Following are the common infections that occur in disaster areas and particularly after the earthquake.
Respiratory Infectious diseases: Most of the earthquake-affected population live in overcrowded evacuation shelters, with inadequate ventilation, poor personal hygiene and unsafe and contaminated water. These are the main predisposing factors for respiratory infectious diseases. The most commonly occurring respiratory infectious diseases during earthquakes are upper respiratory tract infections, influenzas and pulmonary tuberculosis.
Gastrointestinal Diseases: These are also called water and food-borne diseases. These are caused by the ingestion of water and foods contaminated by bacteria, viruses and parasites from human and animal faeces. The most common water and food-borne diseases that occur after earthquakes are acute gastroenteritis, cholera, hepatitis A and hepatitis E, giardiasis and rota virus-associated diarrhoea in children.
Vector-borne diseases: These are the infections transmitted by the bite of infected mosquitoes, mites, and ticks. The most common vector-borne infectious diseases transmitted during the post-earthquake period are malaria, cutaneous and visceral leishmaniasis, scrub typhus, and the Zika virus outbreak.
Wound and skin infections: wound infections depend mainly on the environment in which the injuries take place, the extent of the injury and the microorganisms present on the skin. The traumatic injuries that occur due to earthquakes, adversely affect the immune system and increase the chances of infections. The wound and skin infections that occur during earthquakes are gas gangrene, tetanus, fungal infections and crush syndromes.
Psychological trauma: After the earthquake, survivors often havemental health problems such as post-trauma stress disorder (PTSD) or depression and experience symptoms like anxiety, low mood, emotional ups and downs, and sleep disturbance after the event.
Prevention and control measures: public health responders should rapidly conduct the disease risk assessment to identify the disaster impacts and health needs. There should be an adequate supply of clean water for drinking, proper disposal of excreta and management of solid wastes are essential to prevent outbreaks of diarrhoeal diseases and other vector-borne diseases. All people should ensure regular hand wash with soap and water and take care of proper personal hygiene. All the water storage containers should be well protected and food properly cooked. Chlorine is effective against almost all water-borne pathogens and it is the most affordable and widely available disinfectant for drinking water. It should be used in drinking water.
For malaria and other vector-borne disease control, mosquito nets and the spray of insecticides should be used to prevent the diseases. For dengue prevention improved water storage practices including covering water containers to prevent access to egg laying by female mosquitoes.
Vaccination: measles vaccination is one of the most effective and should be given as soon as people start gathering in the camps. The target age groups are mostly as per the national guidelines.Measles vaccines together with vitamin A supplementation are protective against acute respiratory infections and measles. A proper and focused mental health check-up of all the survivors of the earthquake should be included in the earthquake managementprogrammeand repeated frequently after the disaster.
(The authors are from Department of Trauma and Emergency Medicine All India Institute of Medical Sciences (AIIMS), Jammu)
Follow our WhatsApp channel
