El mercurio en las bombillas de bajo consumo

3. Do mercury emissions due to light bulb use and disposal pose a risk to the environment?

• 3.1 How much mercury is released by different light bulbs during use and disposal?
• 3.2 How much mercury is released into the environment from other sources?
• 3.3 Do mercury releases from light bulbs pose a risk to the environment?

3.1 How much mercury is released by different light bulbs during use and disposal?

The SCHER opinion states:

3.2 Question B
Taking into account the technical and scientific assessment from Öko-Institut and Fraunhofer IZM (2009), assess the potential risks to human health and the environment of the alternatives available to reduce, eliminate or substitute the mercury in CFLs.

In the context of the RoHS directive (2002/95/EC) on hazardous substances in electrical and electronic equipment, the report prepared by the Öko-Institut and Fraunhofer IZM (2009) has reviewed the Hg content in various types of lamps: compact lamps, straight fluorescent lamps for general purposes, straight fluorescent lamps for special purposes and ‘other lamps’ such as high-pressure sodium lamps. However, due to the absence of detailed information on the number of lamps/types used in the EU, on the disposal practices and the life time of the lamps used, the risks to the environment cannot be assessed with the information presented in this report.

The study commissioned by DG TREN and performed by the Flemish institute for technological research (or VITO), has assessed the environmental impact and life cycle of 6 types of lamps, i.e. the so-called base cases (VITO 2009). The information contained in this report allows, be it indirectly, to make an initial risk assessment of Hg contained in these types of lamps. The base cases discussed in this report and used for this opinion are:

1. Incandescent lamp, clear (CLS-C):54W
2. Incandescent lamp, frosted (CLS-F):54W
3. Halogen lamp, low voltage (HL-LV):30W
4. Halogen lamp, mains voltage, low wattage (HL-MV-LW):40W
5. Halogen lamp, mains voltage, high wattage (HL-MV-LW):300W
6. Compact fluorescent lamp, with integrated ballast (CFLi):13W

Exposure assessment based on number of lamps sold in 2007:
The EU-27 electricity consumption in 2007 of non-directional light sources in all sectors is about 112.5 TWh (VITO 2009). This is approximately 4 % of the EU-27 total electricity consumption with 2.95% being used by the domestic sector and 1.05% in the non-domestic sector. The share of each lamp type in the energy consumption for all sectors is given in Table 1.

Table 1: Comparison of unit sales per base case in the EU 27 area

According to the VITO (2009) report, the production of 1 KWh releases 16 ng of Hg into the air; the production of 112.5 TWh in the EU-27 area thus emits 16 x 112.5x109 ng = 1800 kg Hg to the EU-27 air compartment.

An overview of the Hg emission of each lamp type during its use and end-of-life phase is given in Table 2. For example, the 767 million CLS-F lamps which were sold in 2007, released 659.6 kg Hg in the EU-27. This calculation is based on each lamp’s emission of 0.86 mg Hg during its use and end-of-life phases. Similarly, 353 million CFLi units with an emission of 4.51 mg Hg/lamp were sold resulting in a total release of 1592 kg Hg. The higher emission per CFLi unit (4.51 mg/unit) is mainly due to the end-of-life phase (3.2 mg/unit) in which it is assumed that only 20% are recycled. The total Hg release for all lamp types in 2007 was 5264 kg Hg.

Table 2: Hg emissions and sales per lamp type in the EU 27 area

The VITO (2009) report is unclear about the inclusion of possible Hg release during the production phase of the lamps in the assessment. Considering the industrial and local nature of lamp production, the SCHER assumes that these potential Hg emissions will be strictly controlled and managed.

Source & ©: SCHER,  Opinion on Mercury in Certain Energy-saving Light Bulbs (2010), p.10-12.

3.2 How much mercury is released into the environment from other sources?

The SCHER opinion states:

Comparison of Hg release of lamps and some other Hg sources/emissions – comparative risks assessment:
Mercury emissions from both natural sources and anthropogenic activities have been assessed in detail by UNEP (2002). Worldwide release of mercury to the atmosphere is estimated to be between 2,000 and 3,000 metric tons from anthropogenic sources and 1,400 to 2,300, due to natural sources. An assessment covering most likely uses of mercury in the US (based on data from 1995) concluded that mercury emissions into the air from anthropogenic sources amount to 145 metric tons with dental preparations contributing 0.6 tons (UNEP, 2002). An updated assessment for the year 2000 estimated a total anthropogenic release of mercury to the atmosphere of 126 tons and a contribution of 4.5 tons due to the use of dental amalgams. This updated assessment also estimated mercury releases to water from anthropogenic activities (a total of 46 tons, with 0.8 tons from intentional uses including 0.4 tons due to dental amalgams) and to soil (total of 2700 tons, with 106 tons from intentional uses including 28 tons due to dental amalgams) mostly from mining activities (Cain et al. 2007).

The European Environmental Bureau has published a detailed mass balance analysis of mercury used in dental applications (EEB 2007). This report has examined – in a quantitative manner and across the EU-27 - all sources of amalgam Hg and the pathways by which it can enter the environment. This report states that the EU-27 discharges 109 tonnes/y of mercury from dental practices and that mercury in the teeth of deceased persons contributes 14 tons Hg/y to the EU waste stream. The authors state that of this total of 123 tons, 77 tons will ‘likely’ end up in various environmental media: i.e. 30 tonnes in soil, 23 tonnes in the atmosphere, 14 tonnes in surface water and 10 tonnes in groundwater.

The Risk Policy Analysis report estimates that approximately 70 tons Hg/year is released (into the environment) by the EU-15 (Floyd et al. 2002). The value given for Denmark is 1 ton/y which is comparable to the values reported in the above- mentioned report (Danish EPA 2004). No further comparisons of the use quantities, release patterns and possible (predicted) environmental concentrations could be made as the type of information and calculations provided in the various reports is too diverse in nature.

From the literature available to the SCHER it may be concluded that, while dental amalgams may represent one of the major intentional uses of Hg today, the contribution of dental amalgams to Hg emission into the air is only a small fraction of the total release of Hg into the atmosphere. Releases from dental amalgams to water may be more significant, but the relative contributions of the various sources vary considerably depending on the literature source used. Information on the Hg releases of dental amalgams to the soil compartment is too scarce to assess it’s relative importance and potential risks.

Finally, it should be noted that Hg releases associated with the present use of amalgams represent a small fraction of the total Hg emissions into the atmosphere and the global Hg pool due to the much larger emissions from other sources (UNEP 2002).

Source & ©: SCHER,  Opinion on Mercury in Certain Energy-saving Light Bulbs (2010), p.12-13.

3.3 Do mercury releases from light bulbs pose a risk to the environment?

The SCHER opinion states:

Compared to the above-stated 109 tons/y Hg released from dental practices, the Hg emissions originating from electricity production, lamp use and disposal is much lower (approximately 5.3 tons/y, i.e. 4.9 % of Hg originating from dental practices). For elemental Hg and Me-Hg emitted from dental practice amalgams, it was concluded that, except for point sources, no to very low environmental risks are expected. Considering that the Hg emissions from all six types of lamps discussed here is about 20 times lower than that from dental practices emissions, SCHER is of the opinion that environmental risks occurring from Hg released from all lamps, and CLFs in particular, is unlikely.

However, the SCHER would like to point out that for local situations, such as lamp collection and disposal facilities which do not manage potential Hg releases properly, site-specific risks to the environment cannot be excluded. These need to be evaluated taking the site-specific characteristics of the facility and environment into account.

As stated in the answer to question A, the Hg room air concentration after breakage of a CFL is not expected to lead to a health risk for adults. For children, conclusions on the potential risk cannot be provided as the potential contribution of the oral intake route is unknown. Regarding the alternatives and assuming similar release rates after breakage, the short-term peak exposures to Hg will be related to the amount of Hg present. However, peak concentrations of Hg after breakage of lamps with highest Hg concentrations will likely be above long-term occupational limits, but only for a very short time. Therefore, no health risks for adults are expected. Conclusions regarding health risks for children cannot be made due to absence of exposure estimations.

In conclusion, regarding the alternatives, i.e. the six types of lamps listed above, no health risks for adults are expected and the environmental risks are unlikely.

Source & ©: SCHER,  Opinion on Mercury in Certain Energy-saving Light Bulbs (2010), p.13.