Best Practices for X-ray Radiation Control

X-ray radiation has transformed medicine, enabling doctors to see inside the human body without a single incision. But this benefit comes with a responsibility: ionizing radiation, even at low doses, carries biological risks that accumulate over time. The good news is that these risks are highly manageable. With the right protocols and practices in place, exposure to X-ray radiation can be kept well within safe limits – protecting patients, healthcare workers, researchers, and the environment alike. Here is a clear look at the best practices for controlling X-ray radiation, built on decades of guidance from organizations like the International Commission on Radiological Protection (ICRP) and the U.S. Environmental Protection Agency.

The ALARA principle: the foundation of radiation safety 🔗

Every radiation safety framework starts with one guiding idea: ALARA, which stands for As Low As Reasonably Achievable. The Centers for Disease Control and Prevention (CDC) defines it as avoiding exposure to radiation that does not have a direct benefit, even if the dose is small. ALARA is not just a suggestion – it is the practical philosophy that drives all radiation safety decision-making in medical, industrial, and research settings. Three core principles bring ALARA to life in real-world practice: time, distance, and shielding.

Radiation exposure reduction: time, distance, and shielding 🔗

These three principles work together as a system. No single one is sufficient on its own, but when applied in combination, they dramatically reduce the radiation dose received by workers and patients alike.

Time: keep it short 🔗

Radiation dose accumulates directly with duration of exposure. The longer a person remains near an active X-ray source, the higher their total dose. The National Council on Radiation Protection and Measurements (NCRP) emphasizes that reducing exposure time directly and proportionally reduces the dose received. In practice, this means X-ray procedures should be performed efficiently, imaging should only be activated when necessary, and non-essential personnel should leave the room during exposures. In complex fluoroscopy-guided procedures, for instance, the number of imaging pulses should be minimized and the equipment should be switched off between active steps.

Distance: step back significantly 🔗

Distance is one of the most effective and cost-free tools in radiation safety. Radiation intensity does not simply decrease as you move away – it follows the inverse square law, meaning that doubling your distance from the X-ray source reduces your exposure to one-quarter, not one-half. Research published in PMC confirms that two steps back from a mobile X-ray unit can reduce a radiographer’s exposure by around 80%. Moving just 20 centimetres further from the centre of the X-ray field can cut exposure by approximately 73%. The International Commission on Radiological Protection (ICRP) and the NCRP recommend a safe working distance of at least 2 metres from an image intensifier fluoroscopy setup during active imaging, at which point the exposure falls to just 0.025% of the direct beam intensity.

Shielding: put a barrier between you and the source 🔗

When time and distance alone are not enough, physical shielding fills the gap. OSHA guidelines specify that lead is particularly well-suited to attenuating X-rays and gamma rays due to its high atomic number and density. Shielding devices in clinical settings include lead aprons (typically 0.5 mm lead-equivalent), thyroid collars, lead glasses, and leaded gloves. For facility design, the NCRP recommends that shielding in X-ray rooms be designed to limit annual exposure in controlled areas to no more than 5 mGy per year, and to 1 mGy per year in unrestricted public areas. Walls, floors, and ceilings should incorporate lead-lined panels, dense concrete, or leaded glass where needed. Portable or temporary shielding solutions – such as lead bricks or high-density concrete blocks – are also used in industrial radiography. One important caveat: for beta-emitting radionuclides, high-atomic-number materials like lead should be avoided as shielding because they can generate secondary X-rays (Bremsstrahlung radiation).

Preventive measures: reducing radioactive isotope production and managing contamination 🔗

Beyond protecting people from existing X-ray sources, effective radiation control also focuses on minimizing the creation of radioactive byproducts in the first place and safely handling the waste that is inevitably produced.

Minimizing radioactive isotope production 🔗

In laboratory and research settings, good experimental design is the first line of defense. Stanford Environmental Health & Safety advises researchers to minimize waste generation and mixed waste streams from the start – considering during the planning phase which isotopes will be used, their half-lives, and the most efficient quantities. For volatile or airborne radioactive compounds, work must be conducted inside chemical fume hoods with verified airflow, which capture and filter contaminated air before it can spread. Powder-form radioactive materials must always be handled in enclosed systems to prevent aerosolization. These controls directly reduce the volume of radioactive contamination generated and the risk of airborne radioactivity entering the breathing zone of workers.

Safe disposal of contaminated air and radioactive waste 🔗

Air contamination is managed primarily through engineering controls – fume hoods, glove boxes, and negative-pressure enclosures – which prevent radioactive particles from becoming airborne. When contamination does occur on surfaces or equipment, decontamination using mild cleaning agents should be performed promptly, before the material dries and fixes to the surface.

For solid and liquid radioactive waste, proper segregation is essential. University of Washington Environmental Health & Safety recommends separating waste streams by radioisotope and physical form, using lead-shielded containers for photon-emitting (X-ray and gamma-ray) waste and placing containers as far from personnel as practicable. Waste with short half-lives (less than 120 days) can be held in storage for decay before disposal – a practical and cost-effective approach. All containers must be clearly labeled with the radiation symbol and isotope identification. Liquid radioactive waste must not be discharged into sanitary sewers unless approved quantities are confirmed by a Radiation Safety Officer. The U.S. Nuclear Regulatory Commission (NRC) oversees the classification and safe disposal of low-level radioactive waste (such as contaminated gloves, filters, and lab materials) through licensed facilities governed by federal and state regulations.

Safe use of X-rays in medicine: justification, optimization, and dose management 🔗

Medical X-ray use presents a unique challenge. Unlike occupational exposure, patient exposure cannot always be strictly limited by dose thresholds – because for many patients, the benefit of the scan or therapy outweighs the risk of the radiation itself. This is why the ICRP frames medical radiation protection around three principles: justification, optimization, and dose management – not simply dose limits.

Justification: only when necessary 🔗

Justification means that an X-ray or radiation-based procedure should only be performed when it is medically indicated and when the expected clinical benefit outweighs the potential radiation risk. As the ICRP’s guide for medical practitioners states, the aim of radiation management in medicine is to minimize risk without unduly limiting the clear benefits in diagnosis and treatment of disease. This is a critical distinction: ordering a chest X-ray for a patient with respiratory symptoms is clearly justified; repeating a scan without a change in clinical status may not be. Physicians and radiologists have a direct responsibility to evaluate this balance for each individual patient before requesting any imaging or therapeutic procedure.

Optimization: keep doses as low as reasonably achievable 🔗

Optimization in medical X-ray use means using the lowest dose that still achieves the diagnostic or therapeutic goal. In diagnostic imaging, this involves selecting exposure settings appropriate to the patient’s size, using modern dose-efficient equipment, and applying Diagnostic Reference Levels (DRLs) – reference values set at national or regional levels to flag when doses are higher than necessary for a given procedure. According to published research on medical radiation protection, optimization requires that imaging be performed at doses that are as low as reasonably achievable, consistent with the diagnostic task. In radiation therapy, the same principle applies in reverse: the dose to the tumour must be high enough to be effective, while shielding and precise targeting must protect surrounding healthy tissue as much as possible.

Protecting vulnerable populations 🔗

Special precautions apply for children and pregnant patients. Children are more radiosensitive than adults, and certain cancers – like those of the thyroid – are more strongly associated with early-life radiation exposure. For pregnant patients, procedures involving free radioactive iodine (I-131) are contraindicated from around 10-12 weeks of pregnancy onward, when the foetal thyroid becomes functional, to prevent damage to the developing organ. Radiation therapy planning for pregnant patients requires multi-disciplinary review and individually tailored shielding to protect the fetus wherever the beam does not directly target the tumour. For radiation workers of reproductive age, ICRP guidelines recommend that once pregnancy is declared, the additional dose to the embryo or foetus should not exceed 1 mSv for the remainder of the pregnancy.

Occupational dose limits and personal monitoring 🔗

For healthcare and laboratory workers regularly exposed to X-rays, strict dose limits apply. Radiation workers are required to wear personal dosimeters that track cumulative exposure over time. OSHA mandates dosimetry programs in line with federal and state regulations. Workers must also be trained in radiation safety protocols and have access to a Radiation Safety Officer (RSO) who oversees compliance. The use of protective garments – lead aprons, thyroid shields, and leaded glasses – should be routine during fluoroscopy or any procedure where scatter radiation is generated.

What do you think? As medical imaging technology advances and X-ray procedures become more frequent globally, who bears the primary responsibility for ensuring radiation doses stay as low as possible – the individual clinician, the hospital administration, or the regulatory bodies setting the standards? And do you think the current frameworks of justification and optimization are sufficient to protect patients who may be unaware of the cumulative radiation doses they receive across multiple procedures?

References

1. https://www.icrp.org/publication.asp?id=ICRP+Publication+105
2. https://www.epa.gov/radiation/protecting-yourself-radiation
3. https://www.cdc.gov/radiation-health/safety/alara.html
4. https://radcareservices.com/blog/what-are-three-basic-radiation-protection-control-methods/
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC6037814/
6. https://pmc.ncbi.nlm.nih.gov/articles/PMC6611844/
7. https://www.osha.gov/ionizing-radiation/control-prevention
8. https://ehs.stanford.edu/manual/radiation-safety-manual/radioactive-waste
9. https://drs.illinois.edu/Page/SafetyLibrary/UsingRadioactiveMaterials
10. https://www.ehs.washington.edu/radiation/radioactive-waste
11. https://www.nrc.gov/waste
12. https://pmc.ncbi.nlm.nih.gov/articles/PMC4756345/
13. https://www.icrp.org/docs/rad_for_gp_for_web.pdf
14. https://icrpaedia.org/Dose_limits