1. Effects of electromagnetic radiation

(1) Low-frequency electromagnetic field (industrial frequency electromagnetic field)

Source: Power cables (such as strong bridge) are usually laid inside the bridge, which will generate 50/60Hz low frequency electromagnetic field (EMF) after energisation.

Potential Effects:

Long-term exposure: According to the World Health Organisation (WHO) and the International Commission on Non-Ionising Radiation Protection (ICNIRP), the strength of low-frequency electromagnetic fields in the daily environment is well below the safety limit (e.g. 100 μT), and does not generally cause health effects.

Sensitive people: A very small number of people may be sensitive to electromagnetic fields (electromagnetic hypersensitivity, EHS), but there is insufficient scientific evidence.

(2) High-frequency electromagnetic interference (communication bridge)

If communication cables (e.g. optical fibres, network cables) are laid in the bridge, the electromagnetic radiation is extremely small and has basically no effect on the human body.

Recommendation:

Strong power bridge should be laid separately from the weak power bridge (to avoid interference).

Keep a reasonable distance (e.g. ≥ 0.5m) between the bridge and office/residential area to reduce unnecessary electromagnetic exposure.

2. Material safety impact

(1) Metal bridge (galvanised steel, aluminium alloy, stainless steel)

Galvanised bridge: The galvanised surface layer can prevent rust, but if inferior galvanisation or long-term corrosion, it may release trace amounts of zinc, lead and other metal ions (minimal impact).

Aluminium alloy bridge: lightweight and corrosion-resistant, high security.

Stainless steel bridge: corrosion resistance, no harmful substances released.

(2) Non-metallic bridge (FRP, PVC)

Fibreglass reinforced plastic (FRP): corrosion-resistant, but poor quality products may contain volatile organic compounds (VOCs).

PVC bridge: may contain plasticisers (such as phthalates), high temperature may release a small amount of harmful gases.

Suggestion:

Choose high-quality bridges that comply with national standards (e.g. GB/T 19215, IEC 61537).

Prioritise metal bridges in confined spaces (e.g. basements) to reduce the risk of VOCs release.

3. Structural safety impact

(1) Mechanical injury risk

Insecure installation or overloading of the bridge may lead to collapse and injury to personnel.

Sharp edges may scratch maintenance personnel (anti-scratch treatment is required).

(2) Fire performance

Poor quality bridges may promote combustion and release toxic fumes in case of fire (e.g. PVC burning produces hydrogen chloride).

Code Requirement:

Fire-resistant bridges need to pass the fire resistance test (e.g. GB 8624 standard).

Flame-retardant or fire-resistant bridges should be used in high-rise buildings, data centres and other locations.

Recommendation:

Regularly check the fixing of bridges to avoid overloading.

Use fire-retardant material bridges in crowded areas.

4. Static electricity and grounding safety

Metal bridges without good grounding may accumulate static electricity, which may interfere with precision equipment or cause the risk of electric shock.

Code requirements: the bridge must be reliably grounded (GB 50303 ‘Building Electrical Engineering Construction Quality Acceptance Code’).

5. Psychological and aesthetic impact

Exposed bridge may affect the interior aesthetics, resulting in a sense of visual oppression (especially in the home, office space).

Solution:

Use concealed installation (e.g., in suspended ceilings, under floors).

Use coloured or decorative bridges (e.g. aluminium alloy imitation wood grain bridges).