High death rates in March associated with hot weather
Unconfirmed reports suggest that more people, especially the elderly, die in March, from complications of non-communicable diseases such as heart attack and stroke, than any other month of the year.
Previous studies had shown that extreme heat and poor air quality increase complications from underlying heart and respiratory conditions like asthma, renal failure, and pre-term birth, and as temperature rises, there will be more heat-related illness and deaths in both urban and rural areas.
Several studies had shown that March is the hottest month in most parts of Nigeria. Also, researchers have associated very hot weather to high death rates.
Unfortunately, there are no published study, in Nigeria, on the association between perceived or rather unconfirmed high death rates in March and hot temperatures.
However, The Guardian investigation revealed that elderly people with chronic diseases such as diabetes, heart disease and renal damage were more likely to die in March than any other month of the year.
But a public health physician and Executive Secretary, Enugu State Agency for the Control of AIDS (ENSACA), Dr. Chinedu Idoko, told The Guardian: “One cannot exactly say that more people die in a particular month of the year than the other.”
Idoko, who was also Chairman, Enugu State Hospital Management Board, said one could however look at dynamics of the environment, weather, age, sex, health status, and otherwise of individuals/ people and all this would play a role in the mortality rate of a particular people, a particular area at a particular time.
He added: “Furthermore, note that there may also be a time lag to death occurrence and death registration especially in our developing world and all these could lead to death figures observed say at a particular month. Having said this, it is good to observe that the month of March comes strategically at the tail end of the dry season as well as early beginnings of the rainy season in our tropical/ sub-Saharan African environment. This positioning of the month would of course come with it’s own diversities health wise but it is important to note that no one ever died just because of the date.”
Idoko said the commonest causes of death associated with hot weather include dehydration, allergies, high blood pressure and cardiovascular complications, Central Nervous Syndrome (CNS) complications especially arising from meningitis, amongst many others.
The public health physician said possibility of more people dying during the hot weather could be reduced by awareness creation/ enlightenment of the masses to inherent dangers that come with the hot season and extremes of weather, avoidance of dust and other trigger factors by people with different forms of allergies, adequate/ proper medical check-ups and follow-up, adequate aeration and rehydration, and general health promotion measures.
A cardiologist and Executive Secretary, Nigerian Heart Foundation (NHF), Dr. Kingsley Akinroye, told The Guardian that hot temperatures could cause stroke and heart attack. “I cannot say that more people die in March. But it is established that March is the hottest month or one of the hottest months in the country,” Akinroye.
How does heat impact health? According to the World Health Organisation (WHO), heat gain in the human body can be caused by a combination of external heat from the environment and internal body heat generated from metabolic processes.
The WHO document titled “Climate change and human health, Information and public health advice: heat and health, Protecting health from rising temperatures and extreme heat,” noted: “Rapid rises in heat gain due to exposure to hotter than average conditions compromises the body’s ability to regulate temperature and can result in a cascade of illnesses, including heat cramps, heat exhaustion, heatstroke, and hyperthermia. Deaths and hospitalisations from heat can occur extremely rapidly (same day), or have a lagged effect (several days later) and result in accelerating death or illness in the already frail, particularly observed in the first days of heatwaves. Even small differences from seasonal average temperatures are associated with increased illness and death. Temperature extremes can also worsen chronic conditions, including cardiovascular, respiratory, and cerebrovascular disease and diabetes-related conditions.
“Heat also has important indirect health effects. Heat conditions can alter human behavior, the transmission of diseases, health service delivery, air quality, and critical social infrastructure such as energy, transport, and water. The scale and nature of the health impacts of heat depend on the timing, intensity and duration of a temperature event, the level of acclimatisation, and the adaptability of the local population, infrastructure and institutions to the prevailing climate. The precise threshold at which temperature represents a hazardous condition varies by region, other factors such as humidity and wind, local levels of human acclimatisation and preparedness for heat conditions.”
Meanwhile, according a study published in the British Medical Journal, increasing evidence shows that atmospheric carbon dioxide levels are rising and are causing global warming. Record air temperatures were recorded in Britain during the last month. Accurate estimates of the consequences of these must wait until daily mortality data are available, but press reports indicate that the hot weather caused around 1000 deaths during one week alone in Britain and perhaps 10 000 overall in France, where temperatures were higher.
Mortality in Britain is lowest when the mean daily temperature is 17-18°C. The number of heat related deaths per year, obtained as the number of excess deaths on days hotter than this, has averaged around 800 in recent years. Most of those deaths are of people over 70 years of age, and most occur in the first day or two of a period of high temperature.
Few of these deaths are recognisable clinically as being due to heat. Heat stress causes loss of salt and water in sweat, causing haemoconcentration, which in turn causes increases in coronary and cerebral thrombosis. Other deaths in heat waves are probably due to overload of already failing hearts, unable to meet the need for increased cutaneous blood flow in the heat. Very few heat related deaths in British conditions are caused by hyperthermia, overheating sufficient to cause denaturation of the body tissues, but patients unable to sweat because they have diabetic peripheral neuropathy or are taking anticholinergic drugs are known to be at risk in American heat waves. So are patients taking drugs such as barbiturates or phenothiazines, which depress reflex regulation of body temperature. Alcohol can also be dangerous in the heat, both through depression of the central nervous system and by causing diuresis and consequent dehydration.
According to some predictions heat related mortality will increase drastically as global warming develops, but recent evidence is relatively reassuring.
According to the study published in the British Medical Journal, people with heat exhaustion need to be given fluids by mouth and sometimes intravenous saline and dextrose, but by far the most important measures are preventive ones.
Air conditioning can allow people to continue to work effectively in hot weather and may become necessary to prevent mortality, but it uses a large amount of energy, which can itself accelerate global warming. Simpler measures can be very effective in protecting elderly and other vulnerable people from the levels of heat likely to occur in Britain over the next decade.
Continuing to eat regular meals and drink enough water will normally prevent dehydration during heat stress. An open window, fan, light and loose fitting clothing, avoidance of unnecessary exertion, and if necessary sprinkling water on the clothing, can prevent the heat stress.
Such action is effective only if it is taken in time, and it needs to be taken by the general public as well as staff working in homes caring for elderly people. The time to check that windows can be opened, and that a fan is available, is when hot weather is forecast, not when it occurs; delay until temperature reaches a peak may mean that nobody can free a jammed window, or find a fan, for many hours. Elderly people unable to do this themselves, or to get help from relatives or neighbours, need to be given a number to call for help. Brief messages, giving simple advice on these lines in news broadcasts and daily press when hot weather is forecast, could be the most effective way to reduce illness and death in heat waves.
Also, according to a new report from the medical journal The Lancet, climate change is already damaging the health of children, and its impacts will harm the entire generation with serious health problems throughout their lives.
Scientists and health experts from 35 academic institutions and United Nations agencies said that children will suffer from a rise in infectious diseases, malnutrition and air pollution if global warming continues on the current trajectory.
The report’s authors said a child born today will experience a world that is more than 4˚C warmer by the time they turn 71 years old, a rate of warming that will threaten their health at every stage of their life.
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