Systemic Effects
No studies were located regarding respiratory effects in animals or cardiovascular or musculoskeletal effects in humans or animals after oral exposure to boron.
Information on respiratory, gastrointestinal, hematological, hepatic, renal, and dermal/ocular effects is discussed below. The highest NOAEL values and all reliable LOAEL values for these systemic effects for each species and duration category are recorded in Table 2-2 and plotted in Figure 2-2.
Respiratory Effects. Widespread vascular congestion and hemorrhages in the lungs were reported in one infant who ingested 505 mg boron/kg/day (Wong et al. 1964).
TABLE 2-2. Levels of Significant Exposure to Boron and Compounds - Oral
Exposure _LOAEJ__(effect)_
Key to frequency/ NOAEL Less serious Serious figure3 Species Route duration System (mg/kg/day) (mg/kg/day) (mg/kg/day) Reference Form
ACUTE EXPOSURE Death
505 (increased mortali ty) 550 (LD50)
642 (LD50)
510 (LD50)
898 (LD50)
2251 (increased mortali ty)
Wong et BA
al. 1964
Wei r and BA
Fisher 1972
Smyth et BX
al. 1969
Wei r and BX
Fisher 1972
Smyth et BA
al. 1969
NTP 1987 BA
Wei r and BX
Fisher 1972 Wei r and BA
Fisher 1972
Systemi c 9 Human
Reap
505 (vescular congesti on
Wong et al. 1964
Hepatic
Neurologi cal
Renal
Derm/oc
3-5 d Gastro
Derm/oc
1 d Gastro 14 d Gastro hemorrhage in infantes) 505 (parenchymatous degenerati on, jaundi ce, fatty changes, congestion in i nfants) 765 (parenchymatous degenerati on, reduced uri ne output, protein in urine in i nfants)
505 (extensive shedding of ski n)
184 (vomiting, diarrhea in i nfants)
Wong et al. 1964
505 (erythema, desquamati on in infants)
2251 (gastric hyperplasia and dysplasia)
241 (voniting, di arrhea)
Li nden et al. 1986 NTP 1987
INTERMEDIATE EXPOSURE Death
16 Mouse (F) 13 wk Systemi c
505 (perivascular Wong et BA
hemorrhage, al. 1964
congesti on, thrombosi s, edema i n i nfants)
263 (100% Weir and BX
mortality) Fisher 1972
263 (100% Weir and BA
mortaliy) Fisher 1972
144 (increased NTP 1987 BA
mortali ty
Wei r and BX
Fisher 1972 Settimi et BX al. 1982
23.7 (decreased Seal and BX
body and Weeth 1980
spleen weights) 88 (decreased body Weir and BA
weight) Fisher 1972
Wei r and BA
Fisher 1972
44 (decreased packed Wei r and BX
cell volume and Fisher 1972
hemoglobi n)
Neurologi cal
Developmental
25 Mouse (F) 17 d 43.4 Reproducti ve
Settimi et BX al . 1982
, 6b (reduced 28.4 (rib cage fetal defects, weight) increased resorpti ons) 79 (reduced 175.3 (skeletal fetal effects, body weight) increased resorpti ons)
Heindel et BA al. 1991
Heindel et BA al. 1991
100 (testiculr atrophy, decreased enzymes
26 (partial 88 (complete testicular atorphy atrophy) 50 (reduced testi cular enzymes, reduced testicular and epi di dymal wei ght)
of testes)
Dixon et BX
Fisher 1972
Dixon et al. 1979
CHRONIC EXPOSURE Death
26 (partial 88 (complete testicular atrophy of atrophy) of tests
44.7 (impaired spermatogenesi s)
288 (degeneration atrophy of semi ni ferous tubules)
111 (impaired spermatogenesi s, degeneration of semi ni ferous tubules) 29 (testicular atrophy, spermatogeni c arrest) 44 (severe testicular atrophy) 29 (testicular atrophy, spermatogeni c arrest) 44 (severe testicular atrophy)
Wei r and BX
Fisher 1972
Seal and BX
Weeth 1980 NTP 1987 BA
NIEHS 1990 BA
Wei r and BX
Fisher 1972
Wei r and BX
Fisher 1972 Wei r and BA
Fisher 1972
Wei r and BA
Fisher 1972
mortali ty
NTP 1987
Reproducti ve
58.5 (atrophy Weir and BX
of testes, Fisher 1972
decreased testes wei ght)
58.5 (atrophy Weir and BA
of testes, Fisher 1972
decreased ovulati on) 58.5 (atrophy of Weir and BX
testes, Fisher 1972
decreased ovulati on) 58.5 (atrophy of Weir and BA
seminiferous Fisher 1972
tubule epi theli urn, decreased tubule size, decreased testi cular wei ght)
96 (testicular NTP 1987 BA
atrophy, i ntersti ti al hyperplasi a)
Wei r and BA
Fisher 1972 Wei r and BA
Fisher 1972
aThe number corresponds to entries in Figure 2-2.
bUsed to derive an intermediate oral MRL of 0.01 mg/kg/day; dose divided by an uncertainty factor of 1000 (10
for use of a LOAEL, 10 for extrapolation from animals to humans, and 10 for human variability).
BA = boric acid; BX = borax; (C) = capsule; d = day(s); Derm/oc = dermal/ocular; (F) = feed; Gastro =
gastrointestinal; gen = generation; LD50 = lethal dose, 50% kill; LOAEL = 1owest-observed-adverse-effect level; NOAEL = no-observed-adverse-effect level; Resp = respiratory; (W) = water; wk = week(s); yr = year(s)
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