Harmful effects of tobacco use on human health
Tobacco consumption causes preventable illness and premature death.
In the DRC, the mortality proportion due to smoking in 2021 was estimated at 2.18%.
Second-hand smoke is also one of the factors accelerating smoking-related mortality in the DRC.
Tobacco consumption causes serious health problems for smokers and those exposed to tobacco smoke. It remains the leading preventable risk factor for non-communicable diseases. In 2019, more than 8 million people (6.53 million adult men and 2.14 million adult women) worldwide died as a result of consuming tobacco.
Globally, more than 4.05 million tobacco-related deaths occur annually in adults younger than 70 years old.
Active smoking is the main cause of tobacco-related death (7.37 million), followed by passive smoking (1.30 million).
In 2019, 88.29% of the tobacco-related deaths and 86.95% of the tobacco-related disability-adjusted life years (DALYs) were attributable to smoking. In Africa, 146,000 people die every year from smoking.The mortality rate caused by chewing tobacco is also important, mainly due to neoplasms (cancers of the lip, oral cavity, and esophagus).
Globally, there were 55,600 deaths due to chewing tobacco in 2019. The number of deaths related to tobacco consumption in the DRC has increased. The annual number of tobacco-related deaths in the DRC moved from 13,989 in 2015 to 15,231 in 2021.
Effects of tobacco on the body
Tobacco smoke has profound and wide-ranging effects on the human body, contributing to numerous diseases. Additionally, smokeless tobacco, which includes products such as chewing tobacco, snuff, and snus, poses significant health risks despite the absence of smoke inhalation.
An average dose of snuff, held in the mouth for 30 minutes, provides as much nicotine as four cigarettes, so the user reaches a level of nicotine in the blood that is as high or even higher than smoking a cigarette. Snuff is more addictive than chewing tobacco and carries a greater risk of cancer.The effects of smoking tobacco and smokeless tobacco on the body include:
1. Respiratory system
Exposure to smoke, even indirectly, can exacerbate respiratory conditions.
The inhalation of harmful chemicals in tobacco smoke leads to chronic inflammation of the airways, resulting in respiratory diseases.2. Cardiovascular system
Smoking significantly increases the risk of cardiovascular diseases, including coronary artery disease (CAD) and stroke.
The toxic components of tobacco smoke promote atherosclerosis (the buildup of plaques in arteries) and increase the likelihood of blood clots.Recent research has reinforced the link between smoking and cardiovascular diseases, noting that smoking-related cardiovascular damage remains a leading cause of morbidity and mortality worldwide.
3. Reproductive and developmental health
Exposure to tobacco smoke during pregnancy has been linked to adverse developmental outcomes in offspring, including low birth weight, vascular health problems, and congenital disabilities. Research indicates that the use of smokeless tobacco during pregnancy increases the risk of stillbirth and preterm delivery.
4. Oral health
Tobacco contributes to periodontal diseases, tooth loss, oral cancers, and tooth decay.
Additionally, the use of tobacco products, including e-cigarettes, can disrupt the oral microbiome, potentially leading to an increased risk of oral infections and other health complications.
Ailments Caused by Smoking Cigarettes
The figure below describes the effects of smoking in the human body.
Diseases related to tobacco use
Most of the tobacco-related deaths and years lost to disability are due to noncommunicable diseases (NCDs). In the case of tracheal, bronchial, and lung cancer, for instance, tobacco stands as the underlying cause of death in nearly 90% of the cases.
In 2021, more than 7.2 million deaths worldwide were tobacco-related, with around 15,200 deaths in the DRC.Trends in deaths from smoking-related diseases in the DRC (estimates)
Source: Global Burden of Disease (GBD) (2021)
Tobacco/nicotine product use and non-communicable diseases (NCDs)
Chronic respiratory diseases
Chronic respiratory diseases
Tobacco smoke is a major contributor to respiratory diseases, particularly asthma and chronic obstructive pulmonary disease (COPD).
A recent study highlighted the association between tobacco smoke exposure and asthma in children and adolescents, demonstrating that even indirect exposure to smoke can exacerbate respiratory conditions. The inhalation of harmful chemicals in tobacco smoke leads to chronic inflammation of the airways, which can result in persistent coughing, wheezing, shortness of breath, and damage to the lung tissues. In the DRC in 2021, 2.03% of tobacco-related deaths were triggered by respiratory diseases.Cardiovascular diseases
Cardiovascular diseases
Cardiovascular diseases (CVDs) remain one of the leading causes of mortality among smokers.20 Around 7 million strokes and 8 million heart attacks are recorded worldwide.
Tobacco use increases the risk of heart attacks and strokes by promoting atherosclerosis (the hardening and narrowing of arteries) and thrombosis (blood clot formation).Tobacco use has been identified as a significant factor contributing to strokes in intensive care patients at the University Clinics of Kinshasa, with studies estimating that approximately 21% of stroke patients have a history of tobacco consumption.
Given the correlation between smoking and arterial stiffness, tobacco use has emerged as a major risk factor for cardiovascular disease in rural Congolese populations, where smoking rates remain high despite limited access to healthcare.In 2021, about 3 million deaths from CVDs were caused by tobacco use around the world, with about 4,725 deaths in the DRC.20 Global Burden of Diseases (GBD) 2021
Cancer
Cancer
Tobacco use is responsible for 26% of all cancer deaths worldwide.
It contributes to death from 14 types of cancer. While the risk of lung cancer from smoking tobacco has the most widely known effects, smoking can cause cancer almost anywhere in the body, including bladder, blood, cervix, kidney, liver, and many other vital parts.In the DRC, 4.7% of cancer deaths are attributed to tobacco use.
Since tobacco products and passive smoking contain many chemicals harmful to deoxyribonucleic acid (DNA), people who regularly consume tobacco products or are exposed to environmental tobacco smoke have a higher risk of developing cancer. Equally, people who use smokeless tobacco (snuff or chewing tobacco) are at greater risk of developing malignant tumors of the pancreas, esophagus, and mouth. In 2021, about 2.1 million deaths from all types of cancer were caused by tobacco use, and 1,612 of those deaths were recorded in the DRC.Respiratory diseases
Respiratory diseases
Smoking damages the lungs, leading to diseases such as bronchitis and emphysema-pneumonia, two components of COPD.
Additionally, acute respiratory infections, middle ear disease, severe asthma, and stunted lung growth are more common in children exposed to passive smoking. Tobacco use weakens the respiratory system’s defense mechanisms, making smokers more susceptible to infections such as pneumonia and bronchitis. The diagram below presents the death percentage of smoking-attributable diseases in the DRC (2021). It indicates that the death toll of tobacco-related diseases varies. While diseases like tracheal, bronchus, and lung cancer cause more deaths, others like asthma account for fewer deaths.Percentage of deaths caused by smoking-related diseases
Source: Global Burden of Disease (GBD) (2021)
In the DRC, the number of deaths related to NCDs caused by tobacco consumption has been increasing over the years (1990—2021). The oldest age group records the highest number of deaths, with 6,374 deaths among individuals aged 55 and above in 2021. The disease and stroke), chronic respiratory diseases (like COPD), cancers (especially lung cancer), and diabetes. These diseases disproportionately impact older populations, contributing significantly to the rising mortality trend.
Trend of tobacco-related NCD deaths in the DRC by age, 1990-2021 (estimates)
Source: Global Burden of Disease (GBD) (2021)
Tobacco/nicotine product use and communicable diseases
Tuberculosis (TB)
The intersection of tobacco use and infectious diseases, particularly tuberculosis (TB), is a growing concern. Smoking is recognized as an aggravating factor for TB, particularly in areas with high smoking prevalence and limited medical resources. It damages the lungs’ defenses, making them more vulnerable to TB infection and more difficult to treat once infected.
Tobacco smoking doubles the risk of active TB, with an estimated 19.8% of Congolese men being regular smokers, thereby significantly raising the country’s TB burden.
In the DRC, nearly one-sixth of all TB cases and TB deaths were attributable to smoking. The mortality rate of TB caused by smoking in the DRC is estimated at 6%.Impact of smoking on tuberculosis mortality in the DRC
Source: Global Burden of Disease (GBD) (2021)
In addition to TB, tobacco use exacerbates other respiratory infections and emerging communicable diseases, such as COVID-19, significantly impacting public health in the DRC.
Exposure to tobacco smoke increases the risk of lower respiratory tract infections, particularly in children and adults exposed to secondhand smoke. Furthermore, studies show that smokers face a higher likelihood of severe illness, hospitalization, and death from COVID-19 due to compromised lung function and weakened immune responses. In the DRC, where smoking prevalence remains significant, tobacco use has likely worsened outcomes for respiratory diseases, especially among individuals with pre-existing conditions.Lower respiratory diseases
Research shows that tobacco smoke exposure contributes to increased hospitalizations and severe complications from diseases like influenza, pneumonia, bronchitis, and other respiratory viruses.
Lower respiratory tract diseases such as bronchitis, bronchiolitis, and pneumonia are major causes of death in the DRC when considering tobacco as a risk factor. As a matter of fact, in 2021 in the DRC, lower respiratory diseases caused more tobacco-related deaths than TB (3,497 vs. 2,610).These conditions place a substantial burden on the healthcare system, especially in regions with limited access to medical care. Efforts to reduce tobacco use through public health initiatives and policy interventions are crucial in mitigating the impact of communicable diseases related to smoking in the DRC.
Tobacco/nicotine product use and reproductive health
Pregnancy complications (e.g., miscarriage, preterm birth, low birth weight, congenital disabilities)
Smoking during pregnancy is associated with numerous complications, including miscarriage, preterm birth, low birth weight, and congenital disabilities.
Also, Tobacco use negatively impacts fertility in women. Nicotine and other chemicals in tobacco reduce sperm quality and disrupt hormonal balance, leading to difficulties in conception.Smoking during pregnancy introduces numerous risks to both the mother and fetus, with significant adverse outcomes. Toxic substances like nicotine and carbon monoxide disrupt fetal brain development, potentially causing behavioral issues and other complications such as intrauterine growth restriction (IUGR) and preterm birth.
Recent studies confirm that even low levels of smoking during pregnancy lead to heightened risks of preterm births, and the severity increases with higher exposure. Smoking has also been shown to reduce oxygen delivery to the fetus, resulting in long-term developmental challenges, including low birth weight and developmental disorders.Efforts to mitigate these risks focus on smoking cessation, but interventions are often underutilized. Studies show that timely smoking cessation can reduce the risk of complications significantly.
Even when smoking is discontinued in the early stages of pregnancy, there is a reduction in adverse outcomes, including the mitigation of epigenetic risks. Studies emphasize that structured interventions targeting pregnant women are essential for reducing the incidence of complications such as preterm birth and long-term developmental issues in offspring.Fertility in men
Tobacco use negatively impacts fertility in men.
Additionally, men who smoke are at a higher risk of erectile dysfunction due to the adverse effects of tobacco on blood circulation and vascular health. This condition further compounds the reproductive challenges faced by smokers.Fertility in women
Tobacco use negatively affects fertility in women by reducing egg quality and increasing the risk of ectopic pregnancy due to damage to the fallopian tubes.
Smoking also leads to early menopause and challenges with pregnancy, including higher rates of miscarriage, premature birth, and low birth weight. The chemicals in tobacco impair the uterine lining, making it harder for a fertilized egg to implant.Health risks to mother and child
Fetal development issues
Source: Centers for Disease Control and Prevention (CDC) 2024
Tobacco/nicotine product use and health risks to others
Second-hand smoke
The dangers of second-hand smoke are well-documented. Non-smokers exposed to second-hand smoke are at risk of developing similar health problems as smokers, including respiratory diseases, heart disease, and cancer. Passive smoking increases risk of asthma in individuals exposed to second-hand smoke.
Among youth (aged 13 —15) in DRC, 36.8% are exposed to second-hand smoke in public places and 30.2% are exposed at home. In 2021, 4,176 tobacco-related deaths in the DRC were associated with second-hand smoke; more than 4,000 deaths yearly in the DRC have been attributed to passive smoking since 2016. Worldwide, every year, 400 infant deaths and 41,000 non-smoking adult deaths are attributed to exposure to passive smoking.
Evolution of smoking-related mortalityin the DRC from 1990 to 2021
According to estimates by the Institute for Health Metrics and Evaluation (IHME), in 2021, tobacco-related deaths accounted for 10.68% of global deaths. Among these, 9.1% were caused by active smoking, 1.9% by passive smoking (secondhand smoke), and 0.08% by chewing tobacco.
In the DRC, the burden of smoking-related mortality increases over the years. From 1990 to 2021, smoking-related mortality increased from 1.34% to 1.59%.
Specifically, in 2021, tobacco-related deaths accounted for 2.18% of all deaths. Of this total, 1.59% were attributed to active smoking, 0.60% to second-hand smoke exposure, and 0.02% to chewing tobacco. The solution to reducing the number of tobacco-related deaths is therefore to restrict smoking. Although many countries have adopted various strategies to reduce tobacco consumption and achieved beneficial results; more effective measures are still needed.Smoking-related mortality rates evolution (1990-2021)
Source: Global Burden of Disease (GBD) (2021)
E-cigarettes and health impacts
Electronic cigarettes (ECs), commonly referred to as e-cigarettes/vapes, were introduced to the market in 2003 and received international patent protection by 2007.
E-cigarettes were initially promoted as a ”safer” alternative to traditional tobacco products, with researchers touting them as a groundbreaking tool for individuals seeking assistance with quitting smoking. While a large number of people believe that vaping tobacco is a healthy way to quit, there is no strong evidence in the direction of using electronic cigarettes as an effective method of quitting smoking.ECs contain harmful substances, such as propylene glycol, glycerol, liquid flavorings, heavy metals, nicotine, and volatile organic compounds (VOCs).
Formaldehyde, a carcinogen formed when e-cigarette liquid overheats or during ”dry puffs,” can cause airway inflammation up to 10 times more than traditional cigarettes. Chemicals found in EC liquids such as diacetyl, formaldehyde, and vitamin E acetate have been implicated in severe, and sometimes fatal, lung disease.
Cessation and benefits of quitting smoking
In the DRC, awareness about the harms of smoking is being raised through initiatives like the Tobacco Control Data Initiative (TCDI).
However, there is limited research available on the overall public awareness and attitudes toward smoking, making it challenging to fully gauge the extent of understanding across the country.As awareness continues to grow, it is important to highlight the significant health benefits of quitting smoking, which can lead to both short-term and long-term improvements in health. One of the most impactful benefits is the increase in life expectancy.
Life expectancy gained from quitting smoking
Benefits of quitting smoking
Quitting smoking at any age brings health benefits:
- In the short term, it significantly improves cardiovascular health and lung function. Long-term quitters have much lower risks of smoking-related cancers and chronic obstructive pulmonary disease compared to current smokers of the same age.
- One to nine months after quitting smoking, coughing, and shortness of breath decrease. Additionally, structures in the lungs begin to heal and clean the lungs, reducing that person’s risk of infection. This is critical in fighting illnesses that threaten lung health, such as bronchitis.
According to the World Health Organization (WHO), quitting smoking reduces the chances of impotence, difficulty getting pregnant, premature births, babies with low birth weights, and miscarriage.
