Month: November 2025

Coronavirus disease 2019

COVID-19 is a contagious disease caused by the coronavirus SARS-CoV-2. In January 2020, the disease spread worldwide, resulting in the COVID-19 pandemic.

The symptoms of COVID‑19 can vary but often include fever,[7] fatigue, cough, breathing difficulties, loss of smell, and loss of taste.[8][9][10] Symptoms may begin one to fourteen days after exposure to the virus. At least a third of people who are infected do not develop noticeable symptoms.[11][12] Of those who develop symptoms noticeable enough to be classified as patients, most (81%) develop mild to moderate symptoms (up to mild pneumonia), while 14% develop severe symptoms (dyspnea, hypoxia, or more than 50% lung involvement on imaging), and 5% develop critical symptoms (respiratory failure, shock, or multiorgan dysfunction).[13] Older people have a higher risk of developing severe symptoms. Some complications result in death. Some people continue to experience a range of effects (long COVID) for months or years after infection, and damage to organs has been observed.[14] Multi-year studies on the long-term effects are ongoing.[15]

COVID‑19 transmission occurs when infectious particles are breathed in or come into contact with the eyes, nose, or mouth. The risk is highest when people are in close proximity, but small airborne particles containing the virus can remain suspended in the air and travel over longer distances, particularly indoors. Transmission can also occur when people touch their eyes, nose, or mouth after touching surfaces or objects that have been contaminated by the virus. People remain contagious for up to 20 days and can spread the virus even if they do not develop symptoms.[16]

Testing methods for COVID-19 to detect the virus’s nucleic acid include real-time reverse transcription polymerase chain reaction (RT‑PCR),[17][18] transcription-mediated amplification,[17][18][19] and reverse transcription loop-mediated isothermal amplification (RT‑LAMP)[17][18] from a nasopharyngeal swab.[20]

Several COVID-19 vaccines have been approved and distributed in various countries, many of which have initiated mass vaccination campaigns. Other preventive measures include physical or social distancing, quarantining, ventilation of indoor spaces, use of face masks or coverings in public, covering coughs and sneezes, hand washing, and keeping unwashed hands away from the face. While drugs have been developed to inhibit the virus, the primary treatment is still symptomatic, managing the disease through supportive care, isolation, and experimental measures.

Environmental issues have become one of the most discussed global challenges of the 21st century. Human activities have significantly changed natural landscapes, climate systems, and the balance of ecosystems. These disruptions threaten not only wildlife but also human health, food security, and the stability of economies worldwide. Understanding the causes and consequences of ecological problems is the first step toward finding effective solutions.

Causes of Environmental Degradation

Environmental problems are often the result of rapid industrialization, technological development, and unsustainable consumption. The main factors include:

• Industrial pollution – Factories release toxic chemicals and greenhouse gases into the air and water.
• Deforestation – Large areas of forests are cut down for agriculture, urban development, and logging.
• Overuse of natural resources – Excessive mining, fishing, and farming deplete the Earth’s reserves.
• Waste accumulation – Plastic and other non-biodegradable materials contaminate land and oceans.

These human activities disrupt ecosystems and reduce biodiversity, pushing many species toward extinction.

Climate Change and Global Warming

One of the most serious environmental issues is climate change. The burning of fossil fuels increases the amount of carbon dioxide in the atmosphere, trapping heat and raising global temperatures. As a result:

• Ice caps and glaciers are melting.
• Sea levels are rising, threatening coastal cities.
• Droughts, hurricanes, and floods are becoming more frequent.
• Many species are forced to migrate or disappear.

Climate change affects crop yields, water supply, and human health, making it a global issue requiring immediate attention.

Pollution of Air, Water, and Soil

Pollution is another major problem influenced by industrial waste, vehicle emissions, agricultural chemicals, and household trash.

Air Pollution

Air pollution contributes to respiratory diseases, heart problems, and premature deaths. Cities with heavy traffic and industrial zones are especially affected.

Water Pollution

Chemicals and plastic waste contaminate rivers, lakes, and oceans. Marine animals often swallow plastic particles, mistaking them for food.

Soil Pollution

The use of pesticides and industrial dumping reduces soil fertility, making it harder to grow healthy crops.

Loss of Biodiversity

Many animals and plants are disappearing due to habitat destruction, climate change, and illegal hunting. Biodiversity is vital because ecosystems rely on the balance of all species. Losing even one can disrupt the entire chain of life.

Solutions to Environmental Problems

Although the situation is serious, there are many possible solutions:

• Switch to renewable energy such as wind, solar, and hydro power.
• Protect forests through sustainable logging and reforestation programs.
• Recycle and reduce waste, especially plastic.
• Support eco-friendly agriculture that uses fewer chemicals.
• Raise environmental awareness through education and community involvement.

Governments, businesses, and individuals must work together to make meaningful progress.