Respiratory and Cardiovascular Effects of Metals in Ambient Particulate Matter: A Critical Review - Reviews of Environmental Contamination and Toxicology - page 176

evaluated at 24 and 96 h for animals exposed to ROFA, and at 6 and 24 h for animals
instilled with metal sulfates. Basal levels of BALF protein, macrophages, and neu-
trophils were signifi cantly higher in SH rats then normotensive animals. Exposure
to ROFA produced dose-related increases in BALF markers in both SH and WKY
rats, with the effect being more severe in the SH rats. Sulfate solutions of Ni and V
produced inconsistent effects on infl ammatory markers. Ni caused more severe pro-
gressive increases in LDH activity in both strains of rat than V; however, total BALF
cells were signifi cantly increased only at 24 h in Ni exposed rats. V produced an
increase in protein and LDH at 6 h in WKY but not SH rats. Ni and V acted differ-
ently in SH as compared to WKY rats. The authors concluded that rats with com-
promised cardiovascular systems are more susceptible to pulmonary injury from
ROFA metals than normal rats.
Lambert et al. ( 2000 ) evaluated the effects of the same ROFA source used in the
previous studies on sensitization of Brown Norway rats to house dust mite (HDM)
allergens. Rats were instilled with 1,000

ʼ g of ROFA, or 105.12 ʼ g Ni, or 98.2 ʼ g

V, or 58.49 g Fe as sulfates, with mixtures of the metals, or saline controls, fol-

lowed 3 days later with a sensitization dose of HDM. Some of the animals were
sacrifi ced at day 7 after sensitization. At 14 days, the remaining animals were
exposed to a challenge dose of HDM and monitored for immediate bronchocon-
striction in response to the allergen, were then sacrifi ced and evaluated for IgE and
infl ammatory markers. Signifi cant increases in HDM-specifi c IgE were apparent in
all treatment groups, with the greatest increases occurring in animals exposed to
ROFA, Ni, V, or a mixture of metals. Although Fe had only a modest adjuvant effect
on IgE, it produced a greater increase in infl ammatory markers than ROFA or the
other two metals.
The fi nal study using the ROFA obtained from the Florida power plant discussed
here was conducted by Nadadur and Kodavanti ( 2002 ) to investigate effects on the
expression of 84-cardiopulmonary genes coding for proteins involved in infl amma-
tory response, tissue repair, structural and matrix alterations, and vascular contrac-
tility. Following a similar protocol to that used in the previous studies, Sprague
Dawley rats were instilled with saline, 3.3 mg/kg ROFA, 1.3 mmol/kg NiSO 4 , or
2.2 mmol/kg VSO 4 (Table 8 ). Rats were sacrifi ced at 3 or 24 h post-instillation and
blood and lung tissue were evaluated for mRNA activity representing the 84 gene
protein products of interest by gene array data analysis. The authors reported that
the gene expression profi les observed in this study indicate that pulmonary injury
caused by ROFA is different than injury produced by Ni or V acting alone, suggest-
ing potential interactions amongst the constituents in ROFA.

ʼ

ROFA from a Boston Area Power Plant

Wallenborn et al. ( 2007 ) used ROFA designated as PM (HP-12) obtained from the
precipitator of a Boston area power plant to determine if water-soluble metals from
inhaled particulate could translocate to other parts of the body. The water-soluble con-
centrations of Fe, Ni and V were lower in the HP-12 sample than in the Florida power-
plant ROFA used in the previously described studies. Wistar Kyoto rats were instilled