Is Rice in Jeopardy?

Nanomaterials and Damage to Essential Food Crops

Is Rice in Jeopardy?

Many types of nanomaterials[1] are now known to interact with the natural environment, posing a range of new problems. Claims that common nanoforms are relatively immobile in the environment because they are hydrophobic have been largely debunked. Recent experiments show carbon-based nanomaterials form assemblies with natural organic materials under normal environmentally relevant conditions (Hyung et al, 2007). The assemblies are not hydrophobic, and move easily in water and into plant materials. Recent research found nano-organic assemblies were taken up by rice, where they caused delayed growth, reduced yields and cross-generation movement and damage (Lin et al, 2009). Nanomaterials are being disposed of in the environment, making them available to form these assemblies, and leading to serious concerns about the future impacts of nanomaterials on food production and food contamination.

The ecotoxicity of nanomaterials is increasingly documented in the scientific literature (Handy et al, 2008), with behavior and ecotoxicity that varies by material and environment characteristics. Evidence of harm to fish and invertebrates at low concentrations has been reported (Handy et al, 2008; Ferry et al, 2009). Exotoxic effects on microbes and plants have also been reported in a number of studies (Boxall et al, 2007). Phytotoxicity of alumnia nanoparticles was demonstrated in corn, cucumbers, soybeans, cabbages and carrots (Yang and Watts, 2006). The behavior of nanomaterials in water systems has raised questions about the degree to which they can incorporate into food and drinking water (Boxall et al, 2007). Their fate and transport in the environment is the subject of considerable interest (Klaine et al, 2008).

An important question is whether interactions between nanomaterials and the natural environment are plausible. A recent UK publication reported on a fullerene

production facility with a 90% rejection rate for quality control purposes. Imperfect fullerenes were disposed of in a landfill (RCEP, 2008) and so available to interact with natural organic materials. Interaction is not only possible, it is occurring.

Organic-nanomaterial assemblies can move within natural systems and become entrained in water and other cycling systems. Assemblies are in equilibrium, associating and dissociating over time, with free and complexed nanomaterials coexisting (Hyung et al, 2007; Lin et al, 2009). Contamination of water, soil, air and biota from nanomaterial waste can lead to human multimedia exposure (e.g., drinking water, foods, soil dust) and transport via numerous mechanisms, including food chains, commerce, water, and air transport, and waste systems. These processes have been observed over decades for a range of environmental contaminants.

The anticipated pattern of distribution and contamination, combined with durable characteristics, and mobility when complexed with organic materials suggests that some nanomaterials may share the hazardous characteristics of persistent organic pollutants (POPs), that is, persistence, bioaccumulation, toxicity and global transport.

Health hazards of nanomaterials vary, but include damage to lungs, the immune system, genetic material and other systems, as described in extensive toxicological studies.[2] Health risks of organic-nano assemblies have not been studied, but if subjected to human digestive processes designed to break down organic mater, will likely release basic constituents, including nanomaterials.

Of greater concern is potential damage to the food supply. Reductions in yields of rice and other foods could pose substantial health risks. The importance of rice in the world food supply must not be underestimated. Access to safe and sufficient food is a human right that requires protective efforts by all nations (UN, 1974).

Citations

Boxall AB, Tiede K, Chaudhry Q. 2007. Engineered nanomaterials in soils and water: how do they behave and could they pose a risk to human health? Nanomedicine. Dec;2(6):919-27.

Ferry JL, et al. 2009. Transfer of gold nanoparticles from the water column to the estuarine food web Nat Nanotechnol.. Jul;4(7):441-4.

Handy RD, et al 2008. Ecotoxicology of nanoparticles and nanomaterials: current status, knowledge gaps, challenges, and future needs. p315-325. AND

Handy RD et al. 2008 The ecotoxicology and chemistry of manufactured nanoparticles p278-314

Both in Ecotoxicology. May;17(4).

Hyung H, et al, 2007. Natural Organic Matter Stabilizes Carbon Nanotubes in the Aqueous Phase, Environ. Sci. Technol., 2007, 41 (1), pp 179–184.

Klaine et al. 2008. Nanomaterials in the environment: behavior, fate, bioavailability, and effects.

Environ Toxicol Chem. Sep;27(9):1825-51.

Lin S, et al . 2009. Uptake, Translocation, and Transmission of Carbon Nanomaterials in Rice Plants. Small 5(10): 1128–1132.

Royal Commission on Environmental Pollution. 2008. Novel Materials in the Environment: The Case of Nanotechnology. Crown Copyright. Richmond, Surrey, UK

UN, 1974. United Nations Universal Declaration on Eradication of Hunger and Malnutrition, 1974

"Every man, woman and child has the inalienable right to be free from hunger and malnutrition in order to develop fully and maintain their physical and mental faculties."

Yang L, Watts DJ. 2005. Particle surface characteristics may play an important role in phytotoxicity of alumina nanoparticles. Comment in: Toxicol Lett. 2006 Jul 1;164(2):185-7; author reply 1886. (Toxicol Lett. 2005 Aug 14;158(2):122-32.)

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This briefing paper is part of ongoing work to evaluate and address adverse human and ecological impacts of nanomaterials by a network of organizations that are focused on health, environmental sustainability, science, justice, ethics, and human rights.

Kathleen Burns, Sciencecorps; Georgia Miller and Rye Senjen, Friends of the Earth Australia; Mariann Lloyd-Smith, National Toxics Network Australia; Ian Illuminato Friends of the Earth USA.

Recommended contacts: Ian Illuminato at: or Dr. Rye Senjen at

July 13, 2009

[1] Nanomaterials refers to engineered rather than naturally occurring nanomaterials in this paper.

[2] Numerous sources of information on toxicity are available at: