OCCUPATIONAL HYGIENE PRACTICES AND

STANDARDS IN PHYSICAL FACTORS:

NON-IONIZING RADIATION

Alberto Modenese, Fabriziomaria Gobba

University of Modena and Reggio Emilia, Modena, Italy

Scientific Commitee on Radiation and Work ICOH

• Usually EMFs are classified according to their frequencies, OR for the

wavelength.

• NIR can have a natural source (e.g. geomagnetic field, solar radiation) or

an artificial source (e.g. telecommunications, artificial lighting).

NIR= electromagnetic fields (EMF) & optical radiation (OR)

ELECTROMAGNETIC FIELDS

CLASSIFICATION OF ELECTROMAGNETIC RADIATION

(adapted and simplified from WHO) Frequencies

NON-IONIZING

RADIATION (NIR)

Electro Magnetic

Fields EMF

Static Fields 0

Extremely Low

Frequency ELF

>0-300 Hz

Intermediate

Frequency (IF)

>300 Hz-10

MHz

Radio

Frequency (RF)

>10 MHz-300

GHz

Optical Radiation

ORInfraRed /

VISible /

UltraViolet

300 GHz-30

PHz

IONIZING RADIATION (IR) X / Gamma >30 PHz

Industrial

Electrolysis

Cell phone

base station

antennas

MRI scanners and

accidents related to

ferromagnetic

effects

Shortwave diathermy

Other medical EMF appliancations

Transcranial magnetic stimulation

Electric bistoury

EMF-Portal: platform regarding the effects of electromagnetic fields

on humans and on interaction with biological systems or body aids

Number of publications:

2012: ≈ 16,000

2015: > 20,000

2018: > 26,000

2012 – 2018: >10,000

www.emf-portal.de

IARC 2002 ICNIRP 2003 WHO 2006 ICNIRP 2009

IARC 2002 ICNIRP 2003 WHO 2007 ICNIRP 2010

ICNIRP 2009 IARC 2013 WHO (?) ICNIRP (?)

STATIC FIELDS

ELF

RF

ICNIRP 2014

available at:

https://ec.europa.eu/health/scientific_com

mittees/emerging/docs/scenihr_o_041.pdf

DIRECT SHORT TERM EFFECTS OF EMF

EXPOSURE IN HUMANS: LOW FREQUENCIES

MECHANISM: INDUCED CURRENTS (main effect up to 100 kHz)

(THRESHOLDS: induced E-field: V/m, B-field: mT)

o PERCEPTION (e.g. alternating electric charge causing body hair to vibrate)

o EFFECTS ON NERVOUS SYSTEM (E.G. MAGNETOPHOSPHENES,

VERTIGO, NAUSEA, OTHER SENSORY SYMPTOMS) (< 0.1 V/m)

o PERIPHERAL NERVE AND MUSCLE STIMULATION

CONTRACTION (3 V/m, 30 mT)

o EFFECTS ON CARDIAC FUNCTION (EXTRASYSTOLES, CARDIAC

FIBRILLATION (10-25 V/m; 100 - 250 mT)

These effects are induced by very high exposure levels, largely above

the levels currently found in usual conditions in most workplaces

MECHANISM: ENERGY ABSORPTION (thermal effect)

HEATING OF TISSUES (formal threshold > 1°C)

not significant <100 KHz

100 kHz-300 MHz: significant absorption, not uniform (head>trunk)

above 10 GHz: absorption primarily at the body surface

o ALTERATIONS OF THERMOREGULATION, HEAT EXHAUSTION

o PAIN, BURNS

o EYE cataract

o TESTICLE adverse effects to spermatogenesis, etc.

o OTHER

DIRECT SHORT TERM EFFECTS OF EMF

EXPOSURE IN HUMANS: HIGH FREQUENCIES

These effects are induced by very high exposure levels, largely above

the levels currently found in usual conditions in most workplaces

May occur due to the presence of objects in the EMF field, including

interference with medical electronic equipment and other devices

• Interference with active implanted medical devices (MD) or

equipment, such as cardiac pacemakers or defibrillators

• interference with MD worn on the body: e.g. insulin pumps

• interference with passive implants (artificial joints, pins, wires or

plates made of metal)

• Effects on shrapnel, body piercings, tattoos and body art

• Projectile risk from loose ferromagnetic objects in a static field

• Unintentional initiation of detonators

• Fires or explosions from ignition of flammable or explosive material

• Electric shocks or burns from contact currents when a person

touches a conductive object in an electromagnetic field and one of

them is grounded whilst the other is not

SHORT TERM INDIRECT EFFECTS

CONTACT CURRENTS INDUCTION

Near contact of parts of the body with an object at a different

electric potential (not direct contact with power cable); spark

discharge

UP TO 100 kHz about: perception, pain, painful shock ,

muscular contraction, burns, severe shock, breathing difficulties,

etc.; 10 e 100 Hz: lower threshold;

Above 100 kHZ: main effect perception, pain

SHORT TERM INDIRECT EFFECTS

INTERFERENCE (EFFECTS ON MEDICAL DEVICES implanted

or worn, e.g. pacemakers, defibrillators, insulin pumps or others).

EMF may cause a malfunction of the device, related to a

dislocation or to an interference with the sensing function of the

leads

EMF EFFECTS (HUMANS)

LONG TERM

EFFECTS

The hypothesis is that they may

appear also in case of low exposure

levels, currently found in usual

conditions in most workplaces

No agreement on

biological/biophysical mechanism(s)

Scientific evidence of a causal relationship

currently considered not conclusive

CANCER

Main cancer: leukemia, brain tumors (breast cancer, lung, non-

Hodgkin lymphoma, etc.)

IARC classification ELF MF: possible carcinogen (2B)

“Overall, extremely low frequency magnetic fields were evaluted as

possibly carcinogenic to humans (2B), based on the statistical

association of higher level residential ELF magnetic field and increased

risk for childhood leukemia” (IARC 2002)

IARC – Classification of RF fields

RF were classified as possibly carcinogenic to humans (group 2B), based on limited epidemiologic evidence for an association between mobile phone use and risk of glioma (and also for acoustic neuroma), limited experimental evidence in animals, and weak mechanist support

Some members of the working group considered the human evidence inadequate

The evidence related to other RF sources and other tumors was considered inadequateB

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CONCLUSIONS FOR EMF

• Ubiquitous exposure, but very different exposure levels

• Different frequencies inducing biological effects with different

mechanisms

• Direct short term effects appear only in case of very high

exposures (unitntentional exposures, accidents)

• Indirect short term effects: interference with medical devices

may involve workers (at particular risk). No fully safe exposure

levels, specific evaluation are needed condidering the type of

device and the intensity of the EMF

• No agreement on the possibility of long term effects: scientific

literature is still not conclusive

• Needing of specific guidelines for the health surveillance of

exposed workers

OPTICAL RADIATION

- Coherent / non-

coherent

- Artificial / natural

Coherent sources: LASER

Non- coherent sources: UV

Non- coherent sources: visible

Non- coherent sources: infrared

- But the most relevant source of non-coherent optical

radiation is solar radiation.

Considering the health risk

related to occupational exposure:

Infrared (IR),

Visible

Ultraviolet (UV)

Causing the

main adverse

effects.

Carcinogenic

group 1 IARC

(updated 2012)

Main occupational risk factor: OUTDOOR WORK

• Published studies show high levels of

solar UV exposure in: Lifeguards

(Dobbinson et al., 1999; Geller et al, 2001;

Lombard et al., 1991) Watermen/Fishermen

(Bridges et al., 2004; Vitasa et al., 1990)

Farmers, gardeners (Ing et al., 2002;

Marlenga, 1995; Parrott et al., 1996; Rosenman

et al., 1995; Schenker et al., 2002) Mountain

guides (Moehrle et al., 2003) Construction

workers (roofers, carpenters, etc) (Parrott et

al., 1996; Stepanski & Mayer, 1998) Road

workers (Parrott et al., 1996) Ski Instructor

(Rigel et al., 1995)

• Several occupational activities induce a high exposure to UV: outdoor

workers, performing their activities for most of the time outdoor, at risk for

cumuative UV exposure (and related adverse effects), large group of workers

(eg. 15 millions in Europe).

Optical Radiaton

Main mechanisms:

photochemical effects

thermal effects

Main target organs

Eye

Skin

Effects:

Acute

Chronic

Subjects with eye alterations and diseases, as one eyed subjects, subjects

with aniridia, colobomas, drusens, aphakia (or with IOL), or having

diseases/taking drugs causing mydrias, and others.

Subjects with skin (pre)malignant lesions or affected by skin diseases as

scleroderma, systemic lupus erythematosus, pemphigus, xeroderma

pigmentosum, psoriasis, an others.

Subjects with freckles, a high number of moles, fair skin type, family history

for skin cancers.

Subjects taking a chronic therapy with photosensitizing drugs (tetracycline

antibiotics, amiodarone, sulfonamides, etc) or exposed to photosensitizers

(furanocoumarins, psoralen) contained in cosmetics or in plants (e.g. citrus

bergamia)

Co-exposure with other occupationals risks inducing skin cancers, as

arsenic, PAH, untreated or mildly treated mineral oils

Pregnancy (in particular for infrared exposure – heat)

Subjects at particular risk for Optical Radiation exposure

NB: non-exhaustive list

SKIN PHOTOTYPE

individual risk factor for all UV related skin diseases

Interaction Mechanisms

The absorption of UV photons by specific

molecules (chromophore) can lead to breakage

of chemical bonds, formation of new bonds and

formation of free radicals (ROS), highly reactive

chemical species. The damage depends on the

product between duration of exposure and

intensity of radiation. Intense exposures for short

periods are equal to low exposures for longer

periods (reciprocity principle - Bunsen-Roscoe's

Law of Photobiology): so the effect depends on

the dose (product of irradiation for the duration of

exposure).

Thermal effects relates to the temperature

increasing induced by the radiation, and

depends on its duration over time and on

the size of the irradiated surface (and its

thermo-sensitivity). So the damage depends

on the intensity of the exposure

Low exposures, even for long periods, may

induce no harmful effects due to the

dissipation of the thermal energy through

the surrounding tissues.

INTERACTION

PENETRATION

INTO THE SKIN OF

THE RADIATION

MAINLYPHOTOCHEMICAL

MAINLYTHERMAL

SOLAR RADIATION

COMPONENTS

OPTICAL RADIATION

ULTRAVIOLET

ACQUEOUS UMOR

CORNEA

IRISCONJUNCTIVAOPTIC

NERVE

RETINA

MACULA

VITREOUS

LENS

PUPIL

PHOTO-AGING

UV RADIATION

OXIDATIVE DAMAGE

NON-MELANOMA SKIN CANCER(BASAL CELL

CARCINOMA - BCC

+

SQUAMOUS CELL CARCINOMA - SCC)

MALIGNANT MELANOMA - MM

ACTINIC KERATOSES PRE-CANCER

BCC

MM

SUNBURN

Eurogip

SKIN DISEASE WORK RELATED

UK 2002/2005

Turner et al, 2007

Non-Melanoma Skin Cancers (NMSC)

• Squamous Cell Carcinoma (SCC) and Basal Cell Carcinoma (BCC): mostcommon cancers in Caucasians (in US affected 20%) (Kutting 2010; Riegel 2002)

• Main risk factor: UV exposure• Incidence dramatically increased from the 90s, and still increasing• Substantial economic burden: in US cost

= $ 650 million/year (Apalla 2017)

• Solar UVR is the main cause of NMSCs:estimated 50-70% of SCC and 50-90% ofBCC in fair-skinned people (D’Orazio, 2013).

• Two recent meta-analysis on occupationalUVR exposure investigated respectivelyassociation with BCC and with SCC (Bauer et al 2011; Shmit et al, 2011): conclusions= outdoor workers have a significant increased risk for both, with an Odds Ratio of 1.4 (CI 1.23 - 1.66 ) for BCC, based on 23 studies, and of 1.8 (CI 1.4-2.2) for SCC, based on 18 studies.

• NMSC are recognized as occupational diseases in many countries, but despite the evidence based association, they are largely under-reported

Cutaneous Malignant Melanoma

• Risk factors: UV, high number of moles, family history for melanoma, immunosuppression, others;

• melanoma incidence very low in people with dark phototype;

• correlation with other solar skin damage (wrinkling, AK), but risk increases (OR ~1.5) with history ofintermittent sun exposure and sunburn (Kutting 2010 )

• Incidences of melanoma are reported to increase by about 0.6 ± 0.4% (Eide and Weinstock 2005, Slaper et

al. 1996) per 1% increase in ambient annual erythemal dose; ncidence consantly increasing in last 40 years (ozone depletion)

• lack of evidence for a raised incidence of melanoma

in outdoor workers.

• reported inverse association with continuous UV

radiation exposure in adult age (e.g. outdoor

professions) as opposed to intermittent exposure

(e.g. leisure time or childhood exposure).

Armstrong BK, Cust AE. Sun exposure and skin cancer, and the puzzle of

cutaneous melanoma. Cancer Epidemiol. 2017;48:147-156.

E= evolution

Mackie R.M. et al. 2009

Trends in melanoma incidence

UV EFFECTS ON THE EYES

(WHO, 2010)

Chronic

Climatic droplet keratopathy

Pterygium

Pinguecula

Squamous cell carcinoma of the cornea

Squamous cell carcinoma of the conjunctiva

Cataract

Ocular melanoma

Macular degeneration

Acute photokeratitis and conjunctivitis

Acute solar retinopathy

Acute

Acute photo-keratitis/conjunctivitis

Acute solar retinopathy

Eye Effects: Cataract

• The estimated number of blind people worldwide is ≈ 40-50 millions (WHO); about 50% are currenty blind as a result of cataract

• Of these 20 - 22 millions, WHO estimates that as many as 20 % is due to UV exposure

• It is estimated that each 1% sustained decrease in stratospheric ozone would result in an increase of 0.5% in the number of cataract realted to solar UV (WHO)

• The number of blind is expected to double by the year 2025 (Brian, 2001)

• Main morphological forms associated: cortical and nuclear cataract(Modenese & Gobba, 2018)

Macular Degeneration (MD)

• Leading cause of visual impairment for people over 50 years in

developed countries.

• Multi-factorial disease; some known risk factors (e.g. age, smoke,

overweight, alcohol abuse, diabetes) (Chakravarthy et al. 2010)

• A role of SR is proposed

• Possible mechanisms identified (photochemical effects of low

frequency UV-A and blue light, 380-550 nm, lipofuscin accumulation,

inflammatory response, neovascularization pathways) (Nowak,

2006)

• Literature: data concerning occupational SR exposure are scanty, but

there is some epidemiologic evidence of an increased risk for outdoor

workers.

Modenese & Gobba, Int Arch Occ Env Health, 2018

Main mechanisms:

(photochemical effects)

thermal effects

Main target organs

Eye

Skin

Effects:

Acute

Chronic

INFRARED

Skin Effects:

Acute: skin burns; usually induced by 45°C, or 47°C for 10 s,

57°C for 1 ms; pain threshold lower than burn threshold

(ICNIRP 2006)

Chronic: erythema ab igne ; hyperpigmentation, scaling and

telangiectasias of the skin caused by long-term exposure to heat.

Indirect

INFRARED

INFRARED

Eye Effects:

Acute: thermal damage possible to

cornea, lens, retina (1,350- 1,400 nm)

(data limited); defense: aversion

Chronic: thermal damage cornea -

lens (cataract);

Indirect

Indirect Effects:

heat stress

Main mechanisms:

photochemical effects (blue light, 380-550 nm; max 440;

reciprocity: equivalence of effect long low level/short high

level exposures)

thermal effects

Main target organs

Eye: retina (photoretinitis)

Skin

Effects:

Acute

Chronic

VISIBLE

retina most involved; some

frequencies (blue light) more

active in inducing

photochemical injury

Skin: rarely involved

Other: Induction of epileptic

crisis

Indirect Effects :

Photoallergic reactions;

Phototoxic reactions

VISIBLE

ICNIRP, 2013

Up now, insufficient attention to the problem of occupational

exposure to optical radiation

A large body of evidence shows that an additional effort in this

field is urgently needed, in particular to prevent UV related skin

diseases, including cancers, in outdoor workers chronically

exposed to solar radiation

For artificial sources the risk of health effects is lower, but

possibly there are problems with work accidents, in particular for

LASER

CONCLUSIONS FOR OPTICAL RADIATION

CONCLUSIONS

NIR= EMF + optical radiation, a significant physical occupational

risk

Exposure is almost ubiquitous from artificial and natural sources

For EMF, exposure is increasing in last decades, no evidence of

increasing of adverse effects

For optical radiation, exposure decreased for infrared (fusion of the

glass, of metals); decreasing also the number of outdoor workers,

but relevant exposure in last decades due to ozone depletion: UV

related diseases very frequent, and constantly increasing; among

all: skin cancers

For both EMF and optical radiation is not possible to bring the

exposure level to zero; accordingly it is very important the adoption

of adequate preventive measures, both collective and individual

and the recognition of subjects with a particular sensitivity

Thank you for your kind

attention