Comparative life cycle assessment of Long-Lasting Insecticidal Nets including benefits for human health BENOIT VERZAT1, BRUNO FEISTHAUER1, LAURENT DINI2 AND SEBASTIEN HUMBERT1* 1QUANTIS 2BAYER
CROPSCIENCE – ENVIRONMENTAL SCIENCE DIVISION, LYON, FRANCE *CONTACT: SEBASTIEN.HUMBERT@QUANTIS-INTL.COM, +41-79-754-756
CONTEXT and OBJECTIVES Context: LifeNet® a new Long-Lasting Insecticidal Net (LLIN) to fight malaria Bayer CropScience Environmental Science (BCS-ES) developed LifeNet®, the first net composed of polypropylene (PP) multifilament, with deltamethrin incorporated within its fibers Currently, the two main other LLINs used in the field are -
high density polyethylene (HDPE) monofilament with permethrin incorporated (PE net)
-
polyethylene terephthalate (PET) /polyester multifilament with deltamethrin coated on the knitted material (PET net)
Objectives: a comprehensive LCA [1] of these three mosquito nets using Life Cycle Assessment has been done to Identify “hot spots” (in terms of key parameters and life cycle stages) over the life cycle of the three products Identify strategies to be explored further for impact reduction Assess the human health benefits related to mosquito net use and compare them to the adverse potential impacts of net production
Main life cycle stages included in system boundaries
METHOD Functional unit (FU): “offer an efficient protection of persons against malaria with a mosquito net during a period of time encompassing 30 washes”
Raw material production Active ingredient, plastic, anti-UV, master batch
Effectiveness of the LLIN considered as only guaranteed by the persistence of insecticide (based on World Health Organization Pesticide Evaluation Scheme evaluation)
LLIN production Spinning, knitting & finishing, cutting & sewing LLIN distribution Transports (plane, boat, truck)
Background inventory based on ecoinvent and impact assessment based on IMPACT 2002+ v2.2 and USEtox
Use stage Net washing (water, detergent) Effective use rate (physical resistance, comfort)
Specific USEtox characterization factors have been calculated Mosquito nets use phase benefits on human health assessed (protection from mosquito bites and therefore from malaria)
End-of-life Net, packaging
Human health benefits compared to the potential life cycle human health impacts of the nets (contribution from traditional impact pathways such as respiratory effects, toxicity impacts, photochemical ozone formation and from climate change)
RESULTS
Figure 1: Impacts on global warming of the mosquito nets per functional unit
Figure 2: Impacts on human health of the mosquito nets and the DALYs avoided by using a net per functional unit
Global warming score
DALYs Impacts comparison
18
Most impacting life cycle stages regarding all the impacts are together, (1) the net production due to the energy consumption during the spinning and the knitting and finishing steps and (2) the raw material production due to the plastic production
16 Positive DALY = Human health impacts
14
About 0.000015 DALY = 8 min of life time lost related to the entire LLIN life cycle (DALY/FU)
DALYs avoided (human health benefits) by using a net are five orders of magnitude (factor 10’000) higher than the potential impacts generated on human health due to mosquito net production, use and disposal
kg CO2 eq/FU
12 10
Negative DALYs = Human health benefit
8
0.5 DALY avoided by using
6
x -10’000 4
LLINs in Kenya during 3 years → 6 months more life
2 0 LifeNet
PE net
PET net
CONCLUSIONS The most impacting life cycle stages regarding all the impacts are together, the mosquito net production and the raw material production The sensitivity analyses also show that the physical resistance and the end user acceptability are parameters that could strongly influence the overall results Overall the benefits of using a mosquito net are about a factor 10’000 higher than the potential impact to human health generated over the net life cycle
To decrease the overall impact of any mosquito net, the main potential improvements identified are -
to carry on the work of the mosquito net washing material durability in order to increase the durability of the mosquito net
-
to continue efforts to decrease energy consumption during the mosquito net production
-
to ensure adequate communication on safe mosquito net use, including the management of mosquito net packaging to ensure appropriate practices
[1] Quantis. September 2011. Environmental Assessment of Long-Lasting Insecticidal Nets - Polypropylene net (LifeNet), polyethylene net and polyester net. More information: www.vectorcontrol.bayer.com