Further Information Needed  
   
Landscape architects design with multiple objectives in mind, including wildlife conservation, natural aesthetics and recreation. Plant diversity increases both aesthetic enhancement and habitat. In looking at severely polluted brownfields in the last ten years, the research on phytoremediation has focused on scientific aspects—quantifying and maximizing the effectiveness of the plant systems while minimizing the costs. Plants proven successful are targeted and bred to be more successful. Landscape architects need to be involved in directing new research, to come to greater understanding of the patterns of plant choices that will serve to clean or manage toxins on less contaminated urban sites.

Safety is another unknown when using phytoremediation as a tool. Potential hazards that will require research attention and awareness in polluted environments include:
  
   

• Breathing gases released by phytovolatilization;
• Consumption of plant parts by insects, birds, or small rodents of plant parts possibly affecting entire food chain;
• Playing in fallen leaves, or using mulch;
• Vapors and ash residues from burning wood, and;
• Consumption of toxin accumulators in urban gardens in which remediation was not the intent.

  
   
There is no doubt that working parallel to brownfield remediation, there is a role for these plant mechanisms in cleaning our human environments. The toxicity of neighborhood streetside soils is far more prevalent than that of industrial dumps. Not only do we have the potential to correct the sins of the past, we can establish landscapes with additional care for the future.