PHYSICAL CONTAMINATION: CHARACTERISTICS, EXAMPLES - ENVIRONMENT - 2025

The physical contamination is the presence in the environment of any matter or energy to affect the functional quality of the same. Physical pollution occurs both in the form of polluting matter and energies.

Physical pollutants include garbage, noise, artificial lighting, artificial sources of heat and electromagnetic radiation. Of the latter, all electronic devices are included, from a mobile phone to a radar station.

Solid waste pollution. Source:

There are several types of physical pollution, such as solid waste pollution and pollution from sewage and sediment in canals and dams. Also atmospheric pollution by material particles, acoustic, thermal, light and electromagnetic.

An example of the impact of physical pollution in terms of material waste in nature is the plastics in the oceans. These wastes kill many organisms, either by immobilizing them or by suffocating them when ingested.

Another example, in this case of physical pollution as an effect of energy, is the impact of noise pollution on wild birds. Specifically, traffic noise masking mating songs or alarm calls in wild birds.

characteristics

- Definition

All pollution has a physical dimension, since it refers to matter, energy, space-time and their interactions. In any case, there are criteria to differentiate physical contamination from the other two general types of contamination such as biological and chemical.

Differences with biological and chemical contamination

Unlike biological contamination, physics is the product of inert, non-living agents. On the other hand, these pollutants do not alter the molecular composition of the medium where they act unlike chemical pollutants.

- Physical contaminants

A first type of physical pollutant is human-generated waste. Among these is everything that is popularly known as garbage, which in turn can be classified into various types.

These types are determined by their nature as organic and inorganic waste. Within the latter we can speak of electronic waste, debris, plastics and others.

Inert particles in sewage and material particles emitted into the atmosphere are also included.

Other pollutants are the energies that affect the environment causing noise and vibrations, radiation (ionizing and non-ionizing) and changes in temperature.

- Forms of action of physical pollutants

Matter

One way in which physical contamination occurs is through the inclusion of material elements in the environment. For example, pollution from solid waste or garbage, sewage and gases expelled into the environment are material pollutants.

Energy

Similarly, physical pollution can occur due to environmental alteration due to the action of energies on the present matter. Thus, noise is a molecular vibration of the air caused by an energy emitted to the environment.

The heat energy involved in thermal pollution also leads to the atomic vibration of material bodies. In the same way it happens with electromagnetic radiation, except that in this case it propagates even in a vacuum.

- Types of physical pollution and their effects

Solid waste pollution

It includes all kinds of materials, equipment or parts of these that cease to be functional and are discarded. If they are not properly processed either because they are recycled, reused or disposed of in a suitable way, they become pollutants.

An example is garbage dumps or in general garbage accumulations where organic and inorganic waste are mixed.

Sewage and sediment pollution

This is liquid or dissolved waste in sewage that is not of a biological or chemical nature (water and inert particles). Excess sediment in water courses is also included as physical contamination of water.

Solid waste contamination in Lake Maracaibo (Venezuela). Source: The Photographer

For example, when the headwaters of rivers are deforested, the erosion that causes them precipitates sediments into the course. These sediments can clog dams or channels generating overflows, damaging water pumps or making navigation difficult.

Air pollution by particulate matter

In air pollution, in addition to polluting gases, there are material particles in suspension. These fundamentally affect the respiratory system and can cause damage to the health of people according to their susceptibility.

Air pollution in China. Source: See page for author

These particles come from a variety of sources including combustion engines, coal burning, fires, stoves, or heaters. Other sources of particulate matter are foundries, mining, the textile industry, and burning of waste.

Noise pollution

Noise pollution (sonic or sound) is considered noise that is an annoying sound or that alters the conventionally accepted sound environment.

Polluting noise encompasses various sources such as city traffic, machinery, loud music, airplanes, power plants, explosions, and others. In some cases, the determination of noise pollution depends on the sensitivity of the receiver and the circumstances.

Noise pollution from the passage of an airplane in London. Source:

However, there are regulations established based on the information available on the effect of sound levels on human health. In this sense, the WHO considers that the maximum limit of sound intensity to avoid negative effects is 70 decibels (dB).

It has been estimated that the sound intensity at a comfortable level to avoid damage to health is 55 dB. In addition, it is considered that to have an adequate rest at night the noise level should not be greater than 30 dB.

Noise pollution can have psychological effects and cause physical discomfort (migraines, stress, drowsiness, muscle contractures). It can even cause permanent hearing problems depending on the intensity of the sound.

Thermal pollution

It refers to variations in temperature that negatively affect human health or life in general. Particularly the high temperatures that are generated in certain work environments, such as foundries, kitchens and incinerators.

High temperatures cause heat stress exhaustion and reproductive problems in humans, among other conditions.

Thermal pollution in aquatic ecosystems affects the behavior of the species that live there. The reproduction phase of organisms is one of the processes most severely affected by the rise in water temperature.

In animal production systems, heat stress affects productivity, especially by lowering food assimilation rates. In poultry it affects fattening rates and productivity in positions (eggs).

The biggest thermal pollution problem facing humanity today is global warming. In addition to the production of anthropic heat, there is a blockage of the exit of heat radiation towards outer space.

This blockage is produced by particles present in the atmosphere that reflect the heat radiation back to Earth.

Light pollution

Light pollution is the intrusion into nature of artificial light sources causing negative impacts for living beings. Poorly used artificial light causes negative effects on humans and wildlife.

A source of night lighting alters the biological clock of living beings, as it alters their perception of day and night. This causes sleep disturbances in humans, which in turn leads to exhaustion and nervous system problems.

In wild animals it causes alterations in their behavior patterns and in plants it affects their photoperiod. The latter refers to the duration of light and dark cycles that trigger hormonal mechanisms for flowering.

Electromagnetic radiation pollution

Electromagnetic pollution is the environmental displacement of waves produced by the combination of oscillating electric and magnetic fields.

Exposure to high-energy (ionizing) electromagnetic radiation has serious effects on living things. Exposure to gamma rays, X-rays, or ultraviolet radiation can cause serious organ effects, including mutations and cancer.

On the other hand, the effects of non-ionizing electromagnetic radiation, that is to say low energy, are not clearly defined. This type of radiation is caused by electronic devices, such as appliances, microwaves, televisions, and computers.

The mobile phone system, electronic surveillance systems and radars are also considered important sources of electromagnetic radiation.

Although there is no conclusive evidence, it is pointed out that electromagnetic pollution affects health. Among the organ systems affected are the nervous, endocrine, and immune systems.

In the case of animals, negative effects have been clearly demonstrated, for example the decrease in reproductive capacity in storks.

Examples of physical contamination

- Plastic waste in the oceans

One of the most serious physical pollution problems is plastic waste dumped into the oceans. As it is a non-biodegradable material, these wastes remain floating in the water for a long time.

The waste

These wastes are of different nature such as bags, containers, fragments, fishing gear (nets, pots) and others.

Its effect and species most affected

All this debris is transformed into floating traps, as marine animals get entangled in them. This limits their mobility with consequences in terms of possibilities of obtaining food.

Likewise, the turtles must come to the surface to breathe while the sharks and rays must be in motion so that the water passes through their gills.

Turtle caught in a net. Source: Doug Helton, NOAA / NOS / ORR / ERD

There are reports of sharks trapped in plastic involving about 34 different species. The ingestion of pieces of plastic also occurs, causing choking or digestive problems.

- Noise pollution and wild birds

In many species of birds, sound is a fundamental part of their behavior, especially through their songs. The song of the bird is a way to mark territory, evade predators and also to obtain a mate for reproduction.

In addition, the female is able to differentiate between levels of complexity of songs when choosing a partner.

Susceptibility to noise pollution

In this context, various studies have shown the negative impact that noise pollution has on birds. For example, in a forest near a highway, a decrease in bird diversity was detected near the highway.

The birds with a low-pitched song, with frequencies lower than traffic noise, moved away from the highway. While species with frequencies much higher than those of traffic noise were less susceptible to noise pollution.

Some species have even been shown to be able to adjust their sexual call tone in noisy environments.

Acoustic masking

The negative effect of noise pollution on songbirds is caused by what is called acoustic masking. In other words, environmental noises do not allow the song of birds to be adequately perceived by individuals of their species.

An example of this is the musical mosquito net (Phylloscopus trochilus) that experiences difficulties in attracting mates near roads.

In the case of the great tit (Parus major), traffic noise was shown to mask predator alarm calls. This impedes the ability of chickadees to perceive these critical signals and escape danger.

References

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4. Greenpeace. Plastics in the oceans. Data, comparisons and impacts. Press kit. Spain.
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6. Rheindt, FE (2003). The impact of roads on birds: Does song frequency play a role in determining susceptibility to noise pollution? Journal of Ornithology.
7. Templeton, CN, Zollinger, SA and Brumm, H. (2016). Traffic noise drowns out great tit alarm calls. Current Biology.
8. Wantzen, KM (2006). Physical pollution: effects of gully erosion on benthic invertebrates in a tropical clear-water stream. Aquatic Conservation: Marine and Freshwater Ecosystems.