Endocrine disruption: Battle ground for anesthesia.

Ever since the birth of anesthesia in 1846, occupational hazards have invariably accompanied this noble medical specialty. Working in the four walls of operation theater and intensive care unit, filled with various disease causing microorganisms and chemicals while treating patients, the anesthesiologist is continually exposed to risk of multiple diseases. These include blood-borne and air borne infections such as acquired immunodeficiency syndrome, hepatitis, tuberculosis, swine flu and many others, which keeps on arriving in epidemic form. Musculoskeletal morbidity and mechanical injury from objects and equipment as well as due to slips and falls, latex and drug allergy, radiation and magnetic injury, irritation due to laser smoke, fire and explosion hazards and illness due to waste gas exposure constitute a major risk and safety concerns at workplace. Other occupational hazards, which have shown a steadily increasing trend, are drug addiction and substance abuse, stress, fatigue, burnout, and suicides.[12]

Globally, much attention has been paid to waste anesthetic gases (WAG) as an occupational hazard in anesthesia care providers. Gasses which leaks or emanate from breathing circuits into the air during administration of inhalational anesthesia, constitute WAG[34] and mainly belong to halogen family except for nitrous oxide These inhalational pharmacological agents share the structural similarity with a large number of toxic chemicals known as endocrine disruptor chemicals (EDCs).[5] Recently, concern has mounted because of the identification of various endocrine illnesses in operation theatre staff exposed to WAGs. Spontaneous abortions, genetic damage, birth defects in children and cancer have been reported not only in operation theatre staff, but also in their spouses. Though, the plenum and scavenging systems have been enforced in the majority of hospitals in developed nations, the scenario in developing nations still portrays a dismal picture mainly due to socio-economic factors. It is generally observed that the majority of the surgeries are being performed in smaller hospitals, peripheral sectors, and nursing homes where it is extremely difficult to enforce such advanced measures without making each and every one aware of the potential hazards of operation theatre pollution. The methods of exposure, and means of reducing this have been discussed in the literature earlier also but scientific evidence was scarce.[2]

Numerous advancements and significant changes have taken place in modern day anesthesia techniques and practice ever since Vaisman highlighted the higher incidence of spontaneous abortion in Russian anesthetists nearly half a century ago.[6] The chemicals that we use, the plastic and corrugated rubber tubing's employed to deliver a mixture of anesthetic gasses and the scavenging and air conditioning systems that we utilize have changed beyond recognition. What has not changed is the multitude of occupational hazards faced by our colleagues even in times of technological breakthroughs.

In one of the unpublished surveys, it has been discussed that there is a potentially higher “risk” of having female first born off-spring amongst anesthetists in USA. Though, the findings of this survey may be extrapolated, by a mile, to suggest exposure to WAG invite serious focus upon the endocrine and metabolic disruptive effects of various chemicals that anesthetists are exposed to in their work place.

Endocrine disruptors are the substances that interfere with animal or human endocrine systems, and disrupt the physiologic function of hormones. They may be both natural and manufactured (synthetic) chemicals. EDCs are exogenous agents, which interfere with the synthesis, secretion, transport, binding, action or elimination of natural hormones in the body, which are responsible for the maintenance of homeostasis, reproduction, development or behavior. EDCs that anesthesiologists may be exposed to are those present in WAGs, plastic and plastic components, paints and heavy metals (mercury, for example).[7] Polychlorinated biphenyls such as bisphenol A are used extensively as a component of plastic, dental sealants and can linings. Triclosan is a bactericidal agent found in soaps and tooth paste. Triclosan reacts with the free chlorine in tap water to produce other compounds like two, 4-dichlorophenol, which convert into dioxins upon exposure to ultra-violet radiation/light. Some dioxins are extremely toxic, potent disruptors are chemically very stable, and persist in the environment for a very long time. These chemicals may affect the neuroendocrine, thyroid, adrenal, or gonads. Effect on both male and female reproductive systems has been documented.[5]

Apart from the suggested, but not proven, effect of N2O on sperm quality, it also inactivates co-balamin (vitamin B12) to an inactive form, thus reducing vitamin B12 levels and increasing homocysteinemia. These, in turn, are potential risk factors for cardiovascular disease.[8]

Other halogenated gases may impact the reproductive system in a manner similar to that of other EDCs.[9]

Exposure to fumigants, such as formaldehyde, is also a bio hazard. Apart from its irritant properties, it is recognized as a carcinogen. It is not recommended to sterilize the operation theater and critical care units with formaldehyde solution, but still the practice is widely prevalent in many parts of our country and the transition will definitely take some more time.

There is a lot of controversy regarding the causality of the EDCs in the increasing epidemic of reproductive diseases. It will be unethical, (and very difficult) to set up long-term randomized trials to try and prove or disprove cause-effect relationship.

What should be promoted is the “precautionary principle,” which states that lack of absolute scientific evidence should not come in the way of taking action to eliminate possible health hazards to anesthesiologists.[10]

At an individual and professional level, we can take a combined and co-ordinated action to reduce exposure to EDCs. This can be implemented both at the workplace and at the domestic front. Food-related exposure can be reduced by consuming foodstuffs grown by organic farming, i.e. without fertilizers/pesticides. In case this is not possible, use vegetables, which need less pesticide, spray such as roots and tubers. Crops which need comparatively more chemical help to grow, such as ladyfinger, bitter gourd, tomato, should be avoided as far as possible. A thick layer of the skin or rind should be removed while peeling vegetables, which should be immersed in lukewarm or salty water for 10-15 min prior to cutting or cooking.

Plastic-related exposure can be cut by reduce the amount of plastic consumed in the operation theatre. Glass, steel or bone china containers, rather than plastic containers, should be used wherever possible. One should avoid reusing plastic containers such as disposable mineral water bottles. Thinner and softer plastic will have more chemicals, and thus more EDCs than thick, less malleable plastic, and should be avoided.[7]

Chemical-related exposure may be reduced by investigating the chemicals in disinfectants, soaps, and sprays. Less perfumes or deodorants should be used in spray form, and instead, one should patronize traditional powder-based or essence based perfumes, e.g. sandal wood, rose essence.

Water-related exposure can be cut down by ensuring non-reuse of disposable bottles as the plastic bottles left in the car or hot sun for any length of time gets degraded and the plastic molecules get activated by heat, which increases the rate at which the polycarbons leach into the water.

The above discussion, chemically oriented in the nature, should not detract us from other, partially modifiable, factors, which lead to ill-health in anesthesiologists. Lack of physical activity, prolonged sitting or standing in stationary postures, irregular meal timings, consumption of calorie-dense snacks at work, and shift duties (personal observation), all part and parcel of an anesthesiologist's life, are risk factors for metabolic and cardiovascular morbidity (and mortality). Though these are known facts, nothing has been suggested until the date in any book or anesthesia journal to counter such unavoidable routine chores.

Concerted action should be taken by the editors, reviewers and authors of AER to sensitize the anesthesia fraternity to the actual and potential dangers of EDCs. A public health awareness and action plan should be launched to minimize exposure to EDCs, and to reduce unwanted effects on our health.