Handbook of Solvents - George Wypych - ChemTech - Ventech!

1350 Kristen I. McMartin, Gideon Koren
ties of hydrocephalus, agenesis of the corpus callosum, pulmonary hypoplasia and diaphragmatic
hernia, and died 2 hours after birth. In the second case, the mother was exposed
to toluene while manufacturing metal products. The third case had lumbar
meningomyelocele and survived. The mother was exposed to toluene and white spirit. Toluene
air concentrations were not stated.
A case-referent study concerning selected exposures during pregnancy among mothers
of children born with oral clefts was conducted in Finland. 38 The study covered the initial
3.5 years’ material and was a more detailed extension of earlier retrospective studies
concerning environmental factors in the causation of oral clefts, using cases accumulated
from the Finnish Register of Congenital Malformations. More case mothers (14) than referent
mothers (3) had been exposed to organic solvents during the first trimester of pregnancy.
The mothers were considered “substantially” exposed if their estimated continuous exposure
had been at least one-third of the current TLV concentration or if the estimated peak exposure
had reached the TLV concentration, e.g., during home painting in confined spaces.
Various solvents included: lacquer petrol, xylene, toluene, acetates, alcohols, denatured alcohol,
methyl ethyl ketone, dichloromethane, turpentine, styrene, and aromatic solvent
naphtha (C 4-C 14 aromatics).
Ng et al. 39 examined the risk of spontaneous abortion in workers exposed to toluene.
Rates of spontaneous abortions were determined using a questionnaire administered by personal
interview to 55 married women with 105 pregnancies. The women were employed in
an audio speaker factory and were exposed to high concentrations of toluene (mean 88 ppm,
range 50-150 ppm). These rates of spontaneous abortion were compared with those among
31 women (68 pregnancies) who worked in other departments in the same factory and had
little or no exposure to toluene (0-25 ppm) as well as with a community control group of
women who underwent routine antenatal and postnatal care at public maternal health clinics.
Significantly higher rates for spontaneous abortions were noted in the group with higher
exposure to toluene (12.4 per 100 pregnancies) compared with those in the internal control
group (2.9 per 100 pregnancies) and in the external control group (4.5 per 100 pregnancies).
Among the exposed women, significant differences were also noted in the rates of spontaneous
abortion before employment (2.9 per 100 pregnancies) and after employment in the
factory (12.6 per 100 pregnancies).
Tikkanen et al. 17 performed a study to explore for possible associations between occupational
factors and cardiovascular malformations. Information on the parents of 160 infants
with cardiovascular malformations and 160 control parents were studied. The mother
was considered “substantially” exposed to “organic solvents” if the estimated continuous
exposure was at least one third of the ACGIH threshold limit value concentration or the estimated
short term exposure reached the TLV concentration (while painting kitchen walls).
Organic solvents were categorized as 1) “hydrocarbons”, 2) “alcohols” and 3) “miscellaneous”.
Hygiene assessments of exposures were classified as i) “any exposure intensity” (at
any period in pregnancy and in the first trimester only) and ii) “substantial exposure intensity”
(at any period in pregnancy and in the first trimester only).
Of the 320 mothers, 41 case and 40 control mothers reported an exposure to organic
solvents. 16 The hygiene assessment indicated some solvent exposure in 27 case and 25 control
mothers. Twenty-one case and 16 control mothers had been exposed in the first trimester.
Of these, substantial exposure to hydrocarbons occurred for 6 case and 2 control