Air Pollution's Destructive Impact On Ancient Pyramids

The Pyramids of Giza are one of the world's most famous ancient wonders, but they are under threat from air pollution. The air pollution in Cairo is a matter of serious concern and is more than 10 to 100 times the acceptable world standard. The pollution is caused by a variety of factors, including transportation, industry, open-air waste burning, and rice farmers in the Nile Delta burning their chaff. The burning of rice chaff creates acid smog, which is causing the pyramids to crumble. In addition to air pollution, the pyramids are also threatened by rising groundwater tables, earthquakes, and tourists who damage the interiors with graffiti or leave salt encrustations from their breath on the walls.

Air pollution from rice burning

The burning of rice straw, or rice stubble, is a common practice among rice farmers in India, Vietnam, and Egypt. It is a fast and cheap way to clear fields and prepare them for the next planting. However, this practice has been linked to increased air pollution and negative impacts on health and the environment. The smoke from rice burning contains various pollutants, including particulate matter (PM), oxides of nitrogen (NOx), volatile organic compounds (VOCs), and black carbon. These emissions can have detrimental effects on air quality, with the potential to cause or exacerbate respiratory issues and other health problems.

In Egypt, the burning of rice chaff has been identified as a significant contributor to air pollution, particularly in the Nile Delta region. The dense black smoke produced by this practice has been damaging priceless Egyptian antiquities, including the pyramids. The smoke contains acids that react with the calcium in the stone of the pyramids, causing them to become fragile and crumble. The acid from the smoke is also wearing down historic inscriptions on the exterior of tombs and leaving a layer of black grime on Pharaonic monuments, making the ancient stone brittle and crumbly.

The Egyptian Environmental Affairs Agency has stated that the level of pollution caused by rice burning is unacceptable and poses a threat to the nation's historic sites. Dr. Zahi Hawass, Egypt's leading Egyptologist, has expressed concern over the damage caused by the smoke from rice burning to the country's antiquities. Efforts are being made to address this issue, with the Ministry of the Environment investing in scientific research to find alternative uses for rice chaff and develop rice varieties with shorter stems that would require less burning.

In India, the practice of rice straw burning in Punjab has contributed to the country's poor air quality. The smoke from burning rice stalks has affected not only local areas but also regions up to 200 miles away, including the Indian capital, New Delhi. The air quality in New Delhi has been reported to be significantly worse than the levels deemed safe by the World Health Organization. Local governments in India have banned crop burning, and engineers are developing machines to mulch rice stubble instead. However, enforcement of these bans has been inconsistent, and some dispute the extent to which crop burning contributes to air pollution compared to other sources such as traffic and industry.

Similarly, in Vietnam, studies have been conducted to assess the impact of rice residue burning on air quality in Hanoi City. The results suggest a need for further research on atmospheric chemical and concentration modelling to fully understand the seasonal variability and the impact of burning on air pollution levels in the region. Overall, the burning of rice straw or stubble has significant environmental and health implications, and efforts are being made in various countries to reduce this practice and mitigate its negative effects on air quality and historic landmarks, such as the pyramids in Egypt.

Damage to exterior walls

The exterior walls of the pyramids are susceptible to damage from air pollution. The primary threat comes from the burning of rice chaff by farmers in the Nile Delta, which creates dense clouds of black smoke and acid smog. As a result of this burning, carbon dioxide in the air converts more readily into liquid and then into carbonic acid. This acid reacts with the calcium in the stone of the pyramids, causing the exterior walls to become fragile and crumble.

The acid in the smoke has already started to wear down many of the historic inscriptions on the exterior of tombs across Egypt, and a sticky film of black grime has settled on the Pharaonic monuments, including the pyramids, making the ancient stone brittle and crumbly. The smoke from rice burning is threatening to destroy priceless Egyptian antiquities, including hundreds of hieroglyphics in the Valley of the Kings.

In addition to the damage caused by acid smog, the pyramids are also affected by air pollution in the form of carbonaceous gases, which, in an environment of rising humidity, create a black crust on the top parts of the exterior walls. This encrustation is a result of changes in humidity and salinity and has been observed not just on the pyramids but also on other historic buildings in Cairo, such as the Sultan Al-Ghuri Complex, Bab Zuweila, Al-Azhar Mosque, and the Cairo Citadel.

Furthermore, the breath of tourists inside the pyramid chambers contributes to air pollution and creates salt encrustations that crack the interior walls. To mitigate this, ventilation systems have been installed inside the pyramids to lessen the impact of tourists' breath.

Impact of tourism

Tourism accounts for about 10% of the Egyptian economy. However, tourism can also have a detrimental impact on the environment, particularly air quality. A large body of empirical studies has proven that tourism development leads to severe externalities that threaten air quality. The tourism industry is energy-intensive, and almost all sectors, including catering, transportation, retail, and accommodation, have experienced increased demands for heavy energy, resulting in large air pollution emissions.

A study by Higham et al. (2016) found that the demand for transportation, catering, accommodation, and other tourism processes significantly contributed to global air pollution emissions. Therefore, excessive and expanding tourism poses severe challenges to the environmental quality of tourist destinations. The impact of tourism on air pollution varies depending on the mode of tourist arrivals and the region. For example, a study focusing on China found that at the national level, the effect of tourism on PM2.5 emissions exhibits an inverted U-shape, while in eastern China, tourism has a U-shaped impact.

The Pyramids of Giza, one of the seven wonders of the ancient world, are a major tourist attraction in Egypt. While tourism provides economic benefits, it can also contribute to air pollution in the area. The impact of tourism on the air quality around the pyramids is complex and influenced by various factors, including transportation, combustion of fuels, and industrial activities. Tourists visiting the pyramids may arrive by plane, car, or other fossil fuel-powered transportation methods, contributing to air pollution. Additionally, the combustion of fuels used for accommodation and transportation can further increase emissions.

To mitigate the impact of tourism on air pollution, sustainable practices can be implemented. This includes encouraging the use of electric vehicles, promoting renewable energy sources for accommodation and transportation, and implementing comprehensive strategies to address air pollution and climate change. By taking proactive measures, the negative impact of tourism on the environment can be reduced, preserving the ancient pyramids for future generations to experience and enjoy.

Groundwater systems

The groundwater systems in the area surrounding the pyramids are a cause for concern, as they are threatening the structural integrity of the pyramids. The pyramids of Cheops (Khufu), Chephren (Khafre), and Mykerinos (Menkaure) on the Giza plateau have been threatened by a rising groundwater table. This is due to water leakage from irrigation canals and the impact of mass urbanization around the site. The rising water table is caused by a variety of factors, including sewage leakage, factory or agricultural runoff, and inadequate groundwater pumping.

The groundwater systems in the area have two distinct parts. The first is the groundwater aquifer system, which covers the eastern part of the Sphinx area. Here, the groundwater level is relatively shallow, ranging from 1.5 to 4 meters below the surface, with the depth increasing to the west. The second system is linked to water-bearing layers of broken limestone below the Sphinx, where the groundwater depth ranges from 4 to 7 meters.

The impact of these groundwater systems on the pyramids is significant. The rising water table has led to increased salinity in the soil, causing salt depositions on the walls of the pyramids. This, in turn, has resulted in the formation of white crusts, which contribute to the erosion of the stone and the deterioration of the structures. The breath of tourists inside the pyramids also adds to the salt encrustations, causing cracks in the interior walls.

To mitigate the impact of rising groundwater levels, a new water pumping system has been installed at the Giza Plateau. However, this has sparked concerns among ecologists and hydrologists, who worry that the pumping could erode the bedrock under the Sphinx and the nearby pyramids, leading to their potential collapse. The project, financed by USAID, involves 18 advanced water pumps capable of pumping 26,000 cubic meters of water daily. While this may help manage the rising water table, it also highlights the delicate balance between preserving the pyramids and managing the environmental challenges posed by urbanization and irrigation practices in the area.

Seismic activity

The ancient Egyptians were careful to build the pyramids away from seismic zones, ensuring their stability by constructing them on bedrock. This solid foundation, along with the pyramids' geometric form and solid structural engineering, has made them remarkably resistant to earthquakes.

However, the pyramids at Giza have faced severe damage due to seismic activity in recent times. The 1992 Cairo earthquake, with an epicentral distance of about 30 km, caused significant damage to the pyramids. A subsequent restoration plan was implemented to protect them from further degradation and instability.

The pyramids' resilience to earthquakes can be attributed to several factors. Firstly, the ancient Egyptians' careful selection of construction sites away from seismic zones, as mentioned earlier. Secondly, the pyramids' geometric form inherently minimizes the impact of seismic forces. The solid structural engineering, with minimal voids compared to solids, further contributes to their durability. Lastly, the precise construction and attention to detail ensure the overall strength and perfection of the pyramid structure.

While the pyramids have proven to be incredibly resilient against earthquakes, they are not entirely immune to seismic activity. Strong seismic events can cause damage, as evidenced by the 1992 Cairo earthquake. The pyramids' proximity to Cairo also means that they are susceptible to the effects of earthquakes in the surrounding areas, such as the 1995 Aqaba earthquake in east Cairo.

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