{"id":15,"date":"2008-04-02T11:14:51","date_gmt":"2008-04-02T19:14:51","guid":{"rendered":"http:\/\/blogs.edf.org\/nanotechnology\/2008\/04\/02\/getting-to-general-principles-are-we-making-progress\/"},"modified":"2024-02-12T11:00:20","modified_gmt":"2024-02-12T16:00:20","slug":"getting-to-general-principles-are-we-making-progress","status":"publish","type":"post","link":"https:\/\/blogs.edf.org\/health\/2008\/04\/02\/getting-to-general-principles-are-we-making-progress\/","title":{"rendered":"Getting to General Principles: Are We Making Progress?"},"content":{"rendered":"

<\/em>Cal Baier-Anderson, Ph.D.<\/em>, is a Health Scientist.<\/em><\/p>\n

With conventional chemicals, experience has allowed us to articulate general criteria based on chemical properties that identify chemicals of greatest concern.\u00a0 For example, persistent and bioaccumulative chemicals are assigned a high priority, whereas chemicals that quickly degrade and don\u2019t build up in blood or tissue are, as a rule, likely to be of lower priority.<\/p>\n

Concerns about nanomaterials arise from observations that properties that emerge or are greatly enhanced at the nanoscale can alter behavior, including biological activity.\u00a0 These properties make\u00a0such materials different from conventional forms of the same chemicals.\u00a0 But can a general principle that nanomaterials pose a greater concern than their conventional counterparts be supported?\u00a0<\/p>\n

Some nanomaterials have been found to have hazardous properties, while others appear benign, at least under the tested conditions.\u00a0 The major challenge is how to go about identifying the general principles that govern whether a given nanomaterial falls into one or the other category.\u00a0 That is, what key properties of nanomaterials determine whether they are \u201csafe\u201d or \u201crisky\u201d?\u00a0 Is it their size, their large surface area, their surface charge, their shape, some other property or some combination?<\/p>\n

At the Society of Toxicology\u2019s annual meeting in Seattle<\/a>\u00a0last month, the huge diversity of nanomaterial properties was on full display, a dazzling illustration of how complex this new field of study is, how little we really know and understand, and how far we are from uncovering general principles that can be used to guide our decisions.<\/p>\n

Various short-term studies found that certain nanomaterials can translocate from the lungs to the brain, blood, and heart (nano gold); can move from the lungs to the interstitial space, but not the blood (single-walled carbon nanotubes); and either trigger a strong immune response (multi-walled carbon nanotubes) or do\u00a0not (nano zirconium oxide).\u00a0 One study found that, in the blood, silicon-based nanoparticles become coated with proteins, altering the proteins\u2019 shape and increasing the likelihood that the immune system will recognize it as damaged.\u00a0 These are just a few indications of the wide range and nature of biological responses to nanomaterials that complicate our ability to understand and predict their behavior in biological systems.<\/p>\n

My take-home message:\u00a0 We\u2019re nowhere near to deriving general principles.\u00a0 And we still have a lot of hard work to do to get there:\u00a0 Fully characterize the physical and chemical properties of each assessed nanomaterial and examine a broad range of potential biological effects based on all reasonably expected routes of exposure.\u00a0 Only in that way can we begin to correlate nanomaterials\u2019 key physical and chemical properties with their biological properties.\u00a0 The more data we generate \u2013 and the more that is made publicly available for scrutiny and evaluation by the larger nanotoxicology community \u2013 the sooner we\u2019ll get to the general principles we need going forward.<\/p>\n","protected":false},"excerpt":{"rendered":"

Cal Baier-Anderson, Ph.D., is a Health Scientist. With conventional chemicals, experience has allowed us to articulate general criteria based on chemical properties that identify chemicals of greatest concern.\u00a0 For example, persistent and bioaccumulative chemicals are assigned a high priority, whereas chemicals that quickly degrade and don\u2019t build up in blood or tissue are, as a …<\/p>\n","protected":false},"author":101,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[56087],"tags":[39211,5017],"coauthors":[],"class_list":["post-15","post","type-post","status-publish","format-standard","hentry","category-nanotechnology","tag-carbon-nanotubes","tag-risk-assessment"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/posts\/15","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/users\/101"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/comments?post=15"}],"version-history":[{"count":1,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/posts\/15\/revisions"}],"predecessor-version":[{"id":12514,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/posts\/15\/revisions\/12514"}],"wp:attachment":[{"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/media?parent=15"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/categories?post=15"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/tags?post=15"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/blogs.edf.org\/health\/wp-json\/wp\/v2\/coauthors?post=15"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}