In recent years, there has been an increase in the number, magnitude and duration of heat waves around the world, due to the effects of climate change.
The region of the Americas, particularly Mexico, is highly vulnerable to these environmental phenomena that can affect health and increase cases of morbidity and mortality, especially among certain vulnerable population groups.
In the national territory, the first heat wave of the year began on March 17 and according to meteorological forecasts there will be at least four others that will last until September. Until week 21, a total of 1,346 cases of illnesses associated with “extreme natural temperatures” and 61 deaths have been recorded, according to the weekly report for the epidemiological surveillance of extreme natural temperatures, in which a series of recommendations were issued to prevent associated damage.
Beyond cases of dehydration, solar radiation burns, heat stroke, stress or fatigue that are usually related to prolonged exposure to high temperatures, heat waves can aggravate pre-existing cardiopulmonary and kidney diseases, in addition to being a factor risk of cardiovascular disorders.
The Pan American Health Organization (PAHO) noted that mild to moderate effects of heat waves include edema of the lower extremities, syncope or orthostatic hypotension in people taking drugs with a hypotensive effect, cramps due to loss of fluids and electrolytes, as well as heat exhaustion.[1]
These problems are aggravated by the presence of chronic diseases, especially lung, heart and kidney diseases, and by the use of certain drugs. The organization also pointed out that vulnerable people are those who are overweight, elderly and those who carry out outdoor activities, as well as those with limited resources who live in urban areas.
Dr. Arlette Patricia Medina Arellano
“It has been seen that the increase in temperature aggravates respiratory diseases such as asthma, in addition to causing a greater risk of cardiovascular disorders and allergens,” he told Medscape in Spanish Dr. Arlette Patricia Medina Arellano, master in health systems administration and specialist in occupational medicine at the Department of Public Health (DSP) of the Faculty of Medicine of the National Autonomous University of Mexico (UNAM).
The specialist warned that these problems occur especially in susceptible populations, such as pediatrics, who are usually exposed to outdoor spaces when going to school or going out to play, elderly people who regularly present comorbidities or are treated with antihypertensive drugs. or against diabetes, as well as pregnant women.
He added that in addition to these disorders, other associated risks have been documented. For example, among the population that exercises or carries out work in outdoor spaces, especially in the informal sector that does not have adequate protective equipment or medical care services, it has been observed that increased temperatures decrease labor productivity. .
“These workers are more exposed to heat stroke and death from the associated complications. There is also a higher risk of occupational accidents among those who are outdoors and exposed to heat, such as construction workers,” said Dr. Medina.
Dr. Horacio Riojas RodrÃguez
Dr. Horacio Riojas RodrÃguez, surgeon, master of Science in Environmental Health, doctor in epidemiology and director of Environmental Health of the Population Health Research Center of the National Institute of Public Health (INSP), highlighted that heat waves are also associated with vector-borne infections and zoonoses.
“There are well-known diseases, such as dengue, which traditionally had a very marked epidemic curve, since cases occurred during the rainy season, but now in many States of the Republic we have observed outbreaks throughout the year,” he commented to Medscape in Spanish.
Establishing early warning systems is essential
The World Health Organization (WHO) reported that between 2000 and 2016 the population exposed to extreme weather events increased by approximately 125 million people worldwide. In addition to this, between 1998 and 2017, more than 166,000 deaths were recorded due to heat waves, including the one that affected Europe in 2003, with a balance of more than 70,000 deaths.
“These populations have learned to live with heat waves and surely we will all have to do so because of what we have experienced this year in Mexico, as European countries did after the 2003 crisis,” said Dr. Riojas.
The specialist added that in Mexico there are enough historical climatological records to make projections and generate different scenarios to predict how these heat waves could affect population health, although he warned that “the first thing is to act, because if immediate measures are not taken The effects will continue to increase.”
Dr. Medina suggested keeping in mind other conditions related to the sustained increase in temperature, even among accustomed populations, since water scarcity and prolonged droughts could lead to problems of food insecurity and complications such as a greater number of diarrheal diseases or cases. of malnutrition.
Dr. Riojas highlighted that in recent years the epidemiological surveillance system for heat waves in Mexico has improved, which previously “was not very good” because the cases of affected people were not adequately diagnosed or recorded. From his perspective, he has also improved public communication strategies about the risks associated with these phenomena.
However, he recognized that it is also necessary to improve the implementation of preventive early warning systems for the population based on climatological information: “As is already happening in other countries, we want to have early warning systems related to increased heat that prevent these cases. “.
In this sense, the WHO recommends that as heat waves become more frequent and intense in the region of the Americas, Member States should develop action plans that include early warning, preparedness and response measures, not only at the level of the health sector, but at an intersectoral level and covering the different levels of local and national organization.
Faced with these challenges, Dr. Riojas emphasized that the country needs to create a National Environmental Health Program that coordinates the different isolated efforts to face the consequences of climate change on public health through a cross-sector policy, which involves not only the authorities health or environmental, but to other sectors related to this problem: industrial, agricultural, energy and transportation.[2]
This program, whose objective would be to apply comprehensive strategies to prevent and mitigate health risks associated with environmental factors on issues such as climate change, environmental pollution, management of chemical substances, solid waste and water availability, among others, would help avoid gaps that exist, as well as to reduce the morbidity and mortality of exposed populations.
“We continue to think that Mexico requires a National Environmental Health Program like many other countries have and not necessarily in Europe, but also in Latin America, such as Colombia or Brazil, where there is much more concern and willingness to improve environmental and health policies” concluded Dr. Riojas.
Dr. Medina and Dr. Riojas have declared that they have no relevant financial conflicts of interest.