C hapTer 11 nanomaterials and nanotechnologies
478
Many of the existing studies have focused on nanomaterial types
already produced in large bulk form. Titanium dioxide, colloidal
silica, and several iron oxides have been produced for some time in
large production volumes. In some specific instances, for example,
lung inflammation was observed in animal studies with prolonged
inhalation exposures for titanium dioxide, with more adverse
effects present for very small particles compared to larger airborne
particulates. Results are often regarded, however, as inconclusive
and in need of further study. In the literature, hypotheses have been
made that there are more toxicological implications with nanoparticles than with their nonengineered counterparts, but limited data
sets again generally preclude making broadly definitive statements
about health effects so far. Additionally, it has been noted that
the very ability to engineer nanoparticles (including coatings) can
potentially radically change their surface chemistries and effects,
including toward reducing perceived risks.
a specific debate
As discussed in Section 10.4, nanoparticles are finding increasing use
in various kinds of cosmetics, including many types of sunscreens,
lotions, and moisturizers. In sunscreens, titanium dioxide and zinc
nanoparticles are being used to increase the transparency of these
creams while being said to offer UV protection. It is interesting to
look at this particular application as an example of the complexities
of assessing potential health hazards of using nanomaterials and to
look at the surrounding debates as perhaps a bellwether of what is
in store for other applications in which nanomaterials come into
direct contact with humans.
The inclusion of nanomaterials in cosmetics has caused consumer
groups and members of the research community to want to know
more about the safety of doing so. Questioning groups maintain
that nanomaterial applications applied directly to the skin have a
direct pathway to the bloodstream via direct skin penetration. They
also feel that the research on health effects of the kinds of nanomaterials and exposure types on human health are far from conclusive
and that, in the absence of clear findings to the contrary, the large
population of cosmetic users should not be subjected to unknown
risks. They also contend that these products are poorly regulated by
public bodies. Other individuals and groups have challenged these
positions, claiming that the positive value of using sunscreens is
great and that the weight of evidence points to cosmetic products
containing nanomaterials as being safe. There are many nuanced
478
Many of the existing studies have focused on nanomaterial types
already produced in large bulk form. Titanium dioxide, colloidal
silica, and several iron oxides have been produced for some time in
large production volumes. In some specific instances, for example,
lung inflammation was observed in animal studies with prolonged
inhalation exposures for titanium dioxide, with more adverse
effects present for very small particles compared to larger airborne
particulates. Results are often regarded, however, as inconclusive
and in need of further study. In the literature, hypotheses have been
made that there are more toxicological implications with nanoparticles than with their nonengineered counterparts, but limited data
sets again generally preclude making broadly definitive statements
about health effects so far. Additionally, it has been noted that
the very ability to engineer nanoparticles (including coatings) can
potentially radically change their surface chemistries and effects,
including toward reducing perceived risks.
a specific debate
As discussed in Section 10.4, nanoparticles are finding increasing use
in various kinds of cosmetics, including many types of sunscreens,
lotions, and moisturizers. In sunscreens, titanium dioxide and zinc
nanoparticles are being used to increase the transparency of these
creams while being said to offer UV protection. It is interesting to
look at this particular application as an example of the complexities
of assessing potential health hazards of using nanomaterials and to
look at the surrounding debates as perhaps a bellwether of what is
in store for other applications in which nanomaterials come into
direct contact with humans.
The inclusion of nanomaterials in cosmetics has caused consumer
groups and members of the research community to want to know
more about the safety of doing so. Questioning groups maintain
that nanomaterial applications applied directly to the skin have a
direct pathway to the bloodstream via direct skin penetration. They
also feel that the research on health effects of the kinds of nanomaterials and exposure types on human health are far from conclusive
and that, in the absence of clear findings to the contrary, the large
population of cosmetic users should not be subjected to unknown
risks. They also contend that these products are poorly regulated by
public bodies. Other individuals and groups have challenged these
positions, claiming that the positive value of using sunscreens is
great and that the weight of evidence points to cosmetic products
containing nanomaterials as being safe. There are many nuanced