Bahaya guna lampu fluorescent sebab raksa

Bahaya guna lampu fluorescent sebab raksa

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mercury-release-health-effects

1. Why is mercury tolerated in compact fluorescent light bulbs?

Inefficient bulbs will be banned from the market gradually....
Source: EC 

Currently, traditional light bulbs are being phased out in favour of more energy-efficient lamps, mainly compact fluorescent lamps (CFLs) that contain some mercury. Because mercury is a hazardous material, it is generally banned in electric and electronic equipment, but is exceptionally allowed in limited quantities for example in compact fluorescent lamps. At present, it is scientifically and technically impossible to produce mercury-free compact fluorescent lamps, but new technologies can reduce the amount of mercury contained and the authorised content will be gradually lowered. The mercury contained cannot escape from the lamps, except if they break accidentally or if they are discarded with household waste. If consumers take back their burned-out lamps to collection points, the mercury content will be recycled and not released to the environment

The directive on the restriction of hazardous substances in electrical and electronic equipment (2002/95/EC), in short RoHS directive, generally forbids mercury in electronic and electronic equipment with some exemptions in duly motivated cases, such as CFLs. The mercury tolerance for Compact fluorescent lamps is currently set at 5 mg per lamp and is subjected to reviewed on a regular basis.

[Note: It is scheduled to be gradually lowered to 3.5 mg in 2012 and 2.5 mg from 2013 on with some variations depending on the specific lamp type. (Source: amended RoHS directive  )]

The complete elimination of mercury in compact fluorescent light bulbs is still technically and scientifically impracticable though reductions have been achieved. The commission regulation (No 244/2009) implementing the ecodesign directive (2005/32/EC) sets ecodesign requirements that that household lamps, other than light spots, must meet and indicates that the compact fluorescent lamps with the lowest mercury content include no more than 1,23 mg.

 

1. Background

Certain energy-saving light bulbs, namely compact fluorescent lamps (CFLs), are widely available on the market and are offered for saving electricity. They also eventually reduce carbon dioxide emissions particularly from coal-fired power plants. They fulfil the requirements of Commission Regulation (EC) No 244/2009 on ecodesign requirements for non-directional household lamps1 (Ecodesign Regulation), in contrast to traditional incandescent light bulbs which will be phased out progressively in accordance with the Regulation.

According to Directive 2002/95/EC on the restriction of hazardous substances in electrical and electronic equipment (RoHS Directive), a mercury content in CFLs not exceeding 5 mg per lamp is allowed (the mercury exemption for CFLs is listed as n°1 in the Annex to the RoHS Directive). An indicative benchmark (best available technology) of 1.23 mg of mercury in energy efficient CFLs is provided in the above-mentioned Ecodesign Regulation (Annex IV, n° 3 of the Ecodesign Regulation).

The above-mentioned 5 mg mercury tolerance for CFLs is being reviewed on a regular basis, in line with the four-year-review period prescribed by the RoHS Directive. Such reviews aim at assessing whether the elimination or substitution of mercury is technically possible through specific design changes or through the use of other materials, provided that the negative impacts for the environment, health and/or consumer safety generated by the substitution do not outweigh the possible benefits thereof. This is indicated in Article 5 (1.c) of the RoHS Directive.

At the end of 2007, DG Environment commissioned a technical and scientific assessment of this exemption including, among others, consultation of interested stakeholders (e.g. producers of electrical and electronic equipment, environmental organisations and consumer associations). According to this assessment (Öko-Institut and Fraunhofer IZM 2009), finalised in March 2009, the elimination of mercury in CFLs is still technically and scientifically impracticable.

On the basis of this assessment, the Commission will take a decision for the review of this mercury exemption before July 2010, after consultation with the RoHS Technical Adaptation Committee (RoHS Directive, Article 7). In support of any future review, it may further be appropriate to consider the potential risks associated with the release of mercury from a CFL when it accidentally breaks in the hands of a consumer, for example while replacing a CFL. In such a case, long-term toxicological limit values may be exceeded up to 6,000 times, and the consumer's exposure to mercury may only be 10-fold below acute intoxication. Further information can be found in annex 2. Further considerations on the risk from mercury have been published elsewhere (Groth 2008), including in the event of a CFL breakage in a consumer home.

Clean-up of the debris of a broken CFL has been described as complicated, requiring, for example, the removal of the mercury droplets with adhesive tape and their disposal as special waste. This again points to the relevance of the risk caused by the breakage of a CFL in a consumer's home.

As regards the impacts of mercury emissions related to CFLs, the life-cycle of CFLs should be considered so as to weigh the risks of a mercury escape from CFLs, be it by accidental breakage or disposal as waste (instead of an appropriate recycling) against the reduction of mercury emissions from coal-based power plants due to the lower electricity consumption of CFLs (Aucott et al. 2004). Available information indicates that the reduced electricity consumption of CFLs reduces the need for Hg in Energy saving light bulbs electricity, thus the electricity production would release less mercury, and such a decrease could, on balance, save about 10% of the mercury emissions into the environment.

Concerning disposal, Directive 2002/96/EC on waste from electrical and electronic equipment3 (WEEE Directive) requires Member States to adopt appropriate measures in order to minimise the disposal of WEEE, including CFLs, as unsorted municipal waste and to remove mercury from the collected CFLs [see article 5 and Annex II (2) of the WEEE Directive]. A proposal to recast the Directive, made by the Commission in December 2008, strengthens the requirements for separate collection, and specifies that transport of WEEE is to be carried out in a way which optimises the confinement of hazardous substances.

 

2. How could mercury released from a broken CFL affect health?

• 2.1 How can inhaling or swallowing mercury affect health?
• 2.2 Does the amount of mercury released by a broken CFL affect health?

2.1 How can inhaling or swallowing mercury affect health?

If mercury is swallowed less than a thousandth is absorbed by the body and most of it is eliminated, mainly through the urine and faeces. Still, swallowing a high concentration of mercury on the short term can lead to severe harmful and even life-threatening effects.

When inhaled, most of the mercury vapours are absorbed by the lungs. The parts of the body most affected by mercury inhalation are the kidneys and the central nervous system.

People who have accidentally inhaled relatively large quantities of vapours – for instance at certain workplaces – often show inflammation of the lungs, kidney damage, gastroenteritis, restlessness and shaking.

Workers who are exposed regularly to mercury vapours (at levels exceeding German maximum limits for short term exposure at the work place) run an increased risk to develop problems with their central nervous system. Long-term exposure to levels of mercury which are about one quarter of the limit allowed in the workplace, can still harm the kidneys and cause subtle effects on the central nervous system such as memory loss, sleeping problems, anger, fatigue and trembling of the hands.

Young children and the developing are growing and developing quickly so they are particularly vulnerable to mercury. Children exposed to mercury vapours can develop breathing difficulties, swelling and redness of the hands and feet, and pealing pink skin at the tips of fingers and toes. More...

 

2.2 Does the amount of mercury released by a broken CFL affect health?

When the tube of a fluorescent light bulb breaks, the mercury vapour inside is released into the air. In an average room, the amount of vapour could briefly be well above the limits allowed in the general environment, and could exceed the levels allowed in the workplace. However, these limits are designed to protect adults who are exposed to such levels regularly during a 40-year work life, so they are not applicable for a very short-term exposure. Most of the mercury released from the CFL turns liquid very quickly so, shortly after the breakage, the level of mercury vapour becomes too low to cause any harm to adults, even those who are particularly sensitive.

Children breathe in more air in proportion to their size than adults and tend to be more active, so children could be exposed to comparatively higher levels of mercury than adults.

The amount of mercury in the air is not the only important consideration. The spilt mercury that has turned to liquid can stick to surfaces and dust, particularly if the room is not aired sufficiently or cleaned up thoroughly. This is particularly relevant for young children because they bring their fingers and objects to their mouth and may thus swallow contaminated dust.

At present there are no estimates on the amount of mercury that children are likely to swallow after a lamp has broken and the SCHER recommends that this research be carried out and that customers be given instructions on how to deal with a CFL breakage.

The amount of mercury in the air after a compact fluorescent lamp breaks is relatively high initially but is not enough to cause harm. The released mercury vapour turns quickly into a liquid and the level of mercury in the air decreases very rapidly so it is unlikely that broken CFLs pose any risk to the health of adults.

In principle, a foetus can be exposed to mercury through its mother but the amount of mercury that can cross over from the mother’s blood is very limited so the risk of broken CFLs to the foetus is negligible.

At present, there is no data on how much mercury children could take in through swallowing mercury-containing dust or licking contaminated surfaces so it is impossible to determine the risk that broken CFLs pose to children. More...

 

2. How could mercury released from a broken CFL affect health?

• 2.1 How can inhaling or swallowing mercury affect health?
• 2.2 Does the amount of mercury released by a broken CFL affect health?

2.1 How can inhaling or swallowing mercury affect health?

The SCHER opinion states:

3. Opinion 3.1 question A
Assess the possible health risks to consumers, from the mercury released from accidental breakage of CFLs. In doing so, the SCHER is asked to consider risks to certain vulnerable groups of the population such as children or pregnant women.

Toxicology of elemental Hg

Effects of Hg0 inhalation in humans have mainly been characterised after accidental short-term and high-concentration exposures, and after long-term occupational exposures. After inhalation of very high concentrations, orders of magnitude above currently valid occupational exposure limits (e.g., the German MAK-value is 84 μg/m³) symptoms of acute toxicity characterised by restlessness, inflammatory responses in the lung, gastroenteritis and renal damage have been reported. In addition, neurotoxic symptoms such as tremor and increased sensitivity to stimuli are also reported.

After long-term Hg0 inhalation exposures, effects on the central nervous system and kidney apparently are the most sensitive end-points of toxicity. These include effects on a wide variety of cognitive, sensory, personality and motor functions. In general, symptoms subside after removal from exposure. However, persistent effects (tremor, cognitive deficits) have been observed in occupationally exposed subjects 10-30 years after cessation of exposure.

Persons in rooms after breakage of a CFL may be exposed to mercury by inhalation and by oral intake. After inhalation, more than 80% of inhaled Hg0 vapour is absorbed by the lungs. Ingested Hg0 is poorly absorbed in the gastrointestinal tract (less than 0.01%). Skin absorption is insignificant in relation to human exposure to mercury vapour. The elimination of Hg0 after inhalation is slow (half-life of inhaled Hg0 is 60 days) with most being eliminated through urine (as mercury ions) and faeces (as Hg0). A small amount of absorbed Hg0 is also eliminated via exhalation and sweat (ATSDR 1992; Goldman and Shannon 2001; Halbach and Clarkson 1978; Houeto et al. 1994).

Studies on workers exposed to Hg vapour have reported a clear increase in symptoms of dysfunction of the central nervous system at exposure levels greater than 0.1 mg/m³. Some studies also reported subtle neurotoxicity at lower concentrations. Self-reported memory disturbances, sleep disorders, anger, fatigue, and/or hand tremors were increased in workers chronically exposed to an estimated air concentration of 0.025 mg/m³. In a recent assessment of all studies on the exposure-response relationship between inhaled Hg vapour and adverse health effects, IPCS concluded that several studies consistently demonstrate subtle effects on the central nervous system in long-term occupational exposures to mercury vapour at exposure levels of approximately 20 μg/m³ or higher (WHO/IPCS, 2002 Hg).

The kidney is, together with the central nervous system, a critical organ for exposure to mercury vapour. Elemental mercury can be oxidized to Hg²⁺. The kidney accumulates inorganic mercury to a larger extent than most other tissue. High-dose exposure to Hg²⁺ may cause (immune-complex mediated) glomerulonephritis with proteinuria and nephritic syndrome. Effects on the renal tubules, as demonstrated by increased excretion of low molecular proteins, have been shown at low-level exposure, and may constitute the earliest biological effect occurring after long-term exposure to air concentrations of 25-30 μg Hg0/m³.

A large number of serious and even fatal intoxications have been described after ingestion of inorganic mercury compounds, but data from humans do not allow identification of no-adverse exposure levels, especially in long-term exposure. From studies on experimental animals, a No-Observed-Adverse-Effect Level (NOAEL) of 0.23 mg/kg per day was identified (US ATSDR, 1999; WHO/IPCS, 2002)

Children exposed to Hg0 vapours may exhibit symptoms like breathing difficulty, swelling and erythema of the hands and feet, and pealing pink skin at the tips of the fingers and toes. These symptoms are collectively called acrodynia (Albers et al. 1982; ATSDR, 1992, 1999; CDC 1991; Clarkson 2002; Isselbacher et al. 1994; Satoh 2000).

Children and the foetus during various stages of their development are more vulnerable than adults. Fast cell proliferation and migration occur during the second and third trimester of gestation and continues to occur in the first 2-3 years of age. Neural development extends from the embryonic period through adolescence (Rice and Barone, 2000). Since mercury inhibits cell division and migration during development, the foetus and young children are particularly at risk when exposed.

2.2 Does the amount of mercury released by a broken CFL affect health?

The SCHER opinion states:

Exposure assessment

A fluorescent light bulb contains 5 mg of Hg. Assuming release of the total Hg- content of a lamp after breakage into an average room, Hg concentrations in the range of or above occupational exposure limits (100 μg/m³) can be derived. These concentrations are also well above regulatory limits for Hg in a general environment. Regarding environmental exposures, the US EPA has defined a reference concentration (RfC) of 300 ng/m³, and the US CDC derived a maximum residue limit (MRL) of 200 ng/m³. However, it needs to be recognized that these concentrations are applied to life-long inhalation exposures, are based on conservative extrapolations, and are considered protective for all groups of the population, including potentially sensitive subgroups. . The US EPA also has defined an acute RfC of 1.8 μg/m³ for Hg. The acute RfC is an estimate (with uncertainty spanning an order of magnitude) of an acute continuous inhalation exposure (time weighted average with a duration up to 24 hours) without appreciable risks of deleterious effects during a life time for the human population also including sensitive subgroups.

The simple assumption of a complete evaporation of the Hg content from a broken light bulb apparently results in a wide overestimation of air concentrations of Hg over time. Indeed, most of the released Hg may re-condense, due to the low volatility of Hg. Measured data suggest that a broken CFL may produce Hg concentrations of 8 to 20 μg Hg/m³ for a short time after the breakage. Air concentrations rapidly decline: concentrations ≤2 μg Hg/m³ have been measured in a house two days after an Hg spill from a CFL. An experimental study indicates even lower concentrations, between 0.8 and 0.1 μg/m³ Hg0, depending on CFL lamp type, in a room after CFL-breakage (Fig. 1).

Figure 1. Time course of average air concentrations of Hg in a standard room

However, the measured indoor air concentrations may not be indicative of the total Hg intake after a CFL breakage, since most of the Hg released may condense on surfaces, where it can persist if inadequate ventilation is present or in the absence of specific cleanup procedures. Equilibrium between Hg in air and condensed Hg will be reached and then Hg will be slowly oxidized to Hg ions. As a consequence, in addition to inhalation exposure, oral exposure to both elemental Hg and Hg ions may occur in children, due to ingestion of dust and hand-to-mouth contact. There are no data available on the potential contribution of such an exposure to total Hg-intake.

Compared to adults, children have higher exposure via various routes and internal doses of Hg due to several reasons. Children breathe more air per kg of body weight than adults at rest and tend to be more physically active than adults. Therefore, mercury vapours, if present in indoor air, may be delivered to children at higher internal doses than to adults (Miller et al. 2002). The foetus is also exposed during gestation as certain mercury species (HgCH³⁺) cross the placenta. A comprehensive review on mercury exposure in children is available in Counter and Buchanan (2004).

Since no data on the potential contribution of oral exposure to total Hg-intake are available for children, the SCHER recommends assessing potential Hg exposures from broken CFL lamps in an experimental setting specifically considering child behaviour. SCHER also recommends providing to customers specific instructions for Hg removal after breakage of a CFL and info for protecting children.

Based on the room air concentrations determined after breaking a CFL, a health risk for adults is not expected, since the exposure is in the range of occupational exposure limits for only a very short time. The occupational exposure limits are intended to protect adults for a 40-year work life. Due to the very low exposures and their very short duration, even sensitive subgroups in the adult population should be protected.

Given the measured Hg air concentrations after CFL breakage, the rapid decrease of these concentrations and the above-stated considerations on the RfC of Hg, the SCHER is of the opinion that a human health risk for adults due to CFL breakage is unlikely. Regarding risk for children, possible exposures from oral intake of dust and hand-to-mouth contact cannot be evaluated due to lack of scientific data; therefore, no conclusions on potential risk are possible. The external peak exposure to Hg0 by inhalation in adults after a CFL breakage is not translated into a sharp peak exposure of the foetus. Transfer of Hg0 from the maternal circulation to the foetus is limited. Therefore, foetal exposure is expected to be negligible.