Uptake and phytotoxic effect of benzalkonium chlorides in Lepidium sativum and Lactuca sativa.

Cationic surfactants such as benzalkonium chlorides (BACs) are used extensively as biocides in hospitals, food processing industries, and personal care products. BACs have the potential to reach the rooting zone of crop plants and BACs might thereby enter the food chain. The two most commonly used BACs, benzyl dimethyl dodecyl ammonium chloride (BDDA) and benzyl dimethyl tetradecyl ammonium chloride (BDTA), were tested in a hydroponic system to assess the uptake by and phytotoxicity to lettuce (Lactuca sativa L.) and garden cress (Lepidium sativum L.). Individually and in mixture, BACs at concentrations up to 100 mg L-1 did not affect germination; however, emergent seedlings were sensitive at 1 mg L-1 for lettuce and 5 mg L-1 for garden cress. After 12 d exposure to 0.25 mg L-1 BACs, plant dry weight was reduced by 68% for lettuce and 75% for garden cress, and symptoms of toxicity (necrosis, chlorosis, wilting, etc.) were visible. High performance liquid chromatography-mass spectroscopy analysis showed the presence of BACs in the roots and shoots of both plant species. Although no conclusive relationship was established between the concentrations of six macro- or six micro-nutrients, growth inhibition or BAC uptake, N and Mg concentrations in BAC-treated lettuce were 50% lower than that of control, indicating that BACs might induce nutrient deficiency. Although bioavailability of a compound in hydroponics is significantly higher than that in soil, these results confirm the potential of BACs to harm vascular plants.

Nursing leadership in disaster preparedness and response.

Nurses serve as leaders in disaster preparedness and response at multiple levels: within their own homes and neighborhoods, at disaster scenes, and the workplace, which can vary from a health care facility, in the community, or at the state, national, or international level. This chapter provides an overview on theories of leadership with a historical context for nursing leadership; setting the context for nursing leadership in disaster preparedness and response. Although few research studies exist, there are numerous examples of nurses who provide leadership for disaster preparedness and response. To define the current state of the science, the research studies cited in this chapter are supplemented with case studies from particular disasters. The major finding of this review is that nursing leadership in disaster preparedness and response is a field of study that needs to be developed.