Exposure to Nanoparticles and Hormesis

Abstract

ᮀ Nanoparticles are particles with lengths that range from 1 to 100 nm. They are increasingly being manufactured and used for commercial purpose because of their novel and unique physicochemical properties. Although nanotechnology-based products are generally thought to be at a pre-competitive stage, an increasing number of products and materials are becoming commercially available. Human exposure to nanoparticles is therefore inevitable as they become more widely used and, as a result, nanotoxicology research is now gaining attention. However, there are many uncertainties as to whether the unique properties of nanoparticles also pose occupational health risks. These uncertainties arise because of gaps in knowledge about the factors that are essential for predicting health risks such as routes of exposure, distribution, accumulation, excretion and dose-response relationship of the nanoparticles. In particular, uncertainty remains with regard to the nature of the dose-response curve at low level exposures below the toxic threshold. In fact, in the literature, some studies that investigated the biological effects of nanoparticles, observed a hormetic dose-response. However, currently available data regarding this topic are extremely limited and fragmentary. It therefore seems clear that future studies need to focus on this issue by studying the potential adverse health effects caused by low-level exposures to nanoparticles.

Nonlinear Response Amplification Mechanisms for Low Doses of Natural Product Nanomedicines: Dynamical Interactions with the Recipient Complex Adaptive System

“…However, the direction of change from adaptation to a low dose that the organism can survive instead enhances resistance against the adverse effects of the same agent [97,98,[103][104][105]. Furthermore, such beneficial changes can modify responses to not only the same, but also a cross-adapted agent or stressor.…”

“…More than 8,000 scientific papers have now demonstrated hormetic effects as a manifestation of biological plasticity [103]. Low doses of nanoparticles can cause hormesis [105,123]. Other studies have demonstrated that low doses of homeopathically-prepared metals, including cadmium and arsenic, can produce beneficial hormetic reversal of effects of higher, toxic doses of the same or crosssensitized agent on heat shock protein activation patterns [124].…”

The Trend Towards Implementing the Precautionary Principle in US Regulation of Nanomaterials

“…Similarly, it is sufficient to note that there are potential health concerns about exposure to nanomaterials, including the possibility that nanoscale particles may pass through cell membranes, be absorbed through skin, and cross the blood brain barrier (Jordan 2010). There is currently only limited information about the health risks posed by nanomaterials, and much remains unknown about their toxicology (DHHS 2009;Iavicoli et al 2010).…”

Multiweek Resting EEG Cordance Change Patterns from Repeated Olfactory Activation with Two Constitutionally Salient Homeopathic Remedies in Healthy Young Adults

“…Nanoparticles, which are very reactive, can be toxic at relatively higher doses 25 but also elicit salutary hormetic responses at low doses. 26 The homeopathy-fibromyalgia study 1 found that the initial treatment EEG cordance response to sniffing verum homeopathic remedies distinguished patients who subsequently showed an excellent clinical response from patients who had limited clinical benefits from verum and patients who received placebo after 3 months of treatment. Olfactory administration is a less widely used, but nonetheless accepted, mode of treatment.…”