Norman M. Trieff

Cytogenetic, developmental, and biochemical effects of aluminum, iron, and their mixture in sea urchins and mussels

The present study was undertaken to evaluate the toxicity of aluminum sulfate, ferric chloride and their 1:1 mixture (Mix) on early development, fertilization and offspring quality in three sea urchins species (Sphaerechinus granularis, Paracentrotus lividus, Psammechinus microtuberculatus) and in mussels (Mytilus galloprovincialis). The endpoints were the following: a) larval malformations; b) developmental arrest; c) embryonic mortality; d) fertilization success; e) cytogenetic effects, and f) luminol-dependent chemiluminescence (LDCL). Overall data point to the induction of developmental defects in both sea urchin and mussel embryos following exposure of embryos to Al(III) or Fe(III) (10−7 to 10−6 M), whereas Mix caused varied effects vs. Al(III) or Fe(III) alone, from scarce or no additive effects (M. galloprovincialis and P. lividus) to a dramatic rise in embryolethality even at nominal levels of 10−8 M (Ps. microtuberculatus). S. granularis sperm underwent a dose-dependent decrease in fertilization success following exposure to Al(III), or Fe(III), or Mix at levels ranging from 10−8 to 10−5 M. A significant increase of developmental defects was observed in the offspring of S. granularis sperm exposed to micromolar levels of the agents, suggesting an Al(III)- and Fe(III)-related transmissible damage to sperm. The cytogenetic analysis of Al(III)-, Fe(III)-, or Mix-exposed S. granularis embryos showed a significant increase in mitotic aberrations. A relevant feature of the observed cytogenetic damage included scattered chromosomes, suggesting cytoskeleton damage. The LDCL emission in S. granularis embryos showed a dose-related inhibition by agent levels ranging from 10−7 to 10−5 M; this held true for both spontaneous and, to a larger extent, for horseradish peroxidase (HRP)-activated LDCL. LDCL associated with fertilization was affected by Al(III), Fe(III) and Mix, with a time- and dose-related shift from stimulation to inhibition. The changes observed in LDCL emission suggested that the observed damage to embryogenesis, fertilization and mitotic activity may be related, at least partly, to alterations of the embryo prooxidant state. The present data point to developmental, cytogenetic and biochemical changes related to realistic levels of Al(III), Fe(III) and their mixtures, raising concern as to their environmental, occupational and iatrogenic exposures.

Correlation of mutagenic assessment of Houston air particulate extracts in relation to lung cancer mortality rates

Air particulate extracts from a series of solvents were tested in the Ames mutagen detection system and were found to be mutagenic in varying degrees as a function of the particulate collection site in Houston, Texas. The mutagenicity level at seven sites was compared with age-adjusted mortality rates in the same areas. Significant correlation was found with the lung cancer mortality rates but not with mortality rates for other causes. These findings support the hypothesis of a contribution of urban air particulate to the lung cancer rates. Furthermore, these findings suggest that an index of the mutagenicity of air particulate is a more powerful measure of the human health hazard of air pollution than the traditional indices of particulate concentration.

The role of oxidative stress in developmental and reproductive toxicity of tamoxifen.

The antiestrogen tamoxifen (TAM) is widely used as a drug against breast cancer and is currently being tested as a chemopreventive agent. However, a number of studies showed genotoxic and carcinogenic effects of TAM. These effects are thought to be related to oxygen radical overproduction which occurs during TAM metabolic activation. There is no evidence, thus far, on TAM toxicity to embryos and gametes. The present study was designed to elucidate the mechanisms of TAM-induced developmental, reproductive and cytogenetic toxicity towards sea urchin (SU) embryos with regard to the possibility of TAM-initiated oxidative stress. Embryo cultures from SU were subjected to long-term (throughout embryogenesis) or short-term (two hours) incubation with TAM at concentrations from 10(-8) to 10(-5) M. The experiments on TAM-induced toxicity to gametes were carried out with SU sperm, or unfertilized eggs, suspended in TAM (10(-8) to 10(-6) M). To assess the effects of TAM to embryos or to gametes, developmental defects, embryonic mortality, fertilization success, and cytogenetic abnormalities were scored. Oxidative damage to DNA and lipids was detected by measurements of 8OHdG levels and lipid peroxidation, respectively. Reactive oxygen species (ROS) production by eggs and embryos was recorded by luminol-dependent chemiluminescence (LDCL) and cytochrome c reduction methods. The changes in activities of SU superoxide dismutase (SOD) and catalase were also evaluated. TAM exerted: a) early embryonic mortality to exposed embryos and to the offspring of exposed eggs; b) developmental defects to the offspring of exposed sperm; c) decrease in sperm fertilization success, and d) cytogenetic effects in the offspring of exposed sperm or eggs. These morphological effects corresponded to the state of oxidative stress in SU embryos (increased oxidative damage to DNA and lipids and induction of antioxidant enzymes). Since TAM did increase significantly ROS production by embryos, it is suggested that TAM may be metabolically activated by SU embryonic oxidases and peroxidases, which in turn could be induced by TAM. The present study provides further support to the utilization of the SU system as a useful model to help elucidate mechanisms of chemical teratogenesis and carcinogenesis.

Effects on sea urchin fertilization and embryogenesis of water and sediment from two rivers in Campania, Italy

Sea urchin embryos and sperm were utilized for evaluating the toxicity of water and sediment from two rivers, the Sarno (S) River and the Volturno (V) River, in the Campania region, Italy. The effects on developing embryos were evaluated by scoring developmental defects, whereas sperm exposure was tested for the effects on fertilization and offspring quality. Ten sampling sites from the rivers (S.1–S.4 and V.1–V.6) were monitored for water and sediment quality. Water sampling was carried out biweekly for a year (1988–1989); the samples were tested at dilutions 10−4 to 10−2 in natural seawater. Sediment tests were carried out on solid phase samples (collected in 1989 to 1992), at concentrations ranging from 2 to 10 mg/ml (dry wt) in seawater. The tests conducted on water samples mostly led to nonsignificant results in either embryo-or spermiotoxicity, possibly due to sharp changes in pollutant levels in the water column. Unlike water, sediment samples displayed clear-cut results both on embryogenesis and on fertilization success. The grain size of sediment failed to reveal any relationship with toxicity, which could only be referred to the presence of toxic contaminants (Melluso et al., 1993). The most polluted sediment samples displayed a dramatic embryo-toxicity, up to approximately 87% developmental arrest in embryos reared in 2 mg/ml of sediment from site S.1 (affected by leather tanning effluent). These results were independent of storage conditions of sediment samples (i.e., at +4°C or −20°C). A decrease in fertilization success was also induced by sediment samples from polluted sites (not by a relatively unpolluted reference sample). Interestingly, sediment spermiotoxicity appeared to be related to storage temperature in samples from two agricultural sites (S.3 and V.6), in that freezing caused a drop in sample spermiotoxicity compared to refrigeration; e.g., a sample from site V.6 stored at +4°C decreased fertilization rate (FR) to 9% versus a control value of 86%, whereas the same sample induced but a minor change following storage at −20°C (FR=68%).In general, a better reliability was observed for sediment bioassays than for water bioassays, thus suggesting that future biomonitoring studies should mainly focus on sediment quality. The use of solid phase sediment in toxicity testing by sea urchin embryos and sperm is warranted by the present results.

Effluent from bauxite factory induces developmental and reproductive damage in sea urchins

The effluent from a bauxite plant was tested on sea urchin embryos and sperm for the induction of: a) developmental defects in effluent-exposed embryos; b) loss of fertilization success, and c) transmissible damage to the offspring of pretreated sperm. The chemical composition of the bauxite sludge was analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Dose-related effects were observed at effluent dilutions ranging from 1:105 to 1:102 [equal to 1.5 to 1,500 μg (dry weight)/ml]. The effects were exerted on developmental toxicity, spermiotoxicity, and offspring malformations/mortality. Toxicity was exerted by sludge concentrations in the order of 1:103 (or 150 μg/ml). Chemical analysis of sludge pointed to the presence of several inorganics, with prevalence of aluminum, iron and chromium. In spite of the recognized difficulties in referring the effects of complex mixtures (bauxite sludge) to the toxicities of individual components, the results reported here are fairly consistent with those reported on the toxicities of the major sludge components. Based on the present data, uncontrolled disposal of bauxite sludge may be a major hazard(s) to the environment, involving early life stages and recruitment in aquatic biota.

The evaluation of mutagenicities of 19 structurally related aromatic amines and acetamides in Salmonella typhimurium TA98 and TA100

19 aromatic amines were assayed for mutagenicity using Salmonella typhimurium strains TA98 and TA100 with and without the addition of S9 from Aroclor-1254-induced rat liver. These included: naphthalenes (1-amino-, 1-acetamido-, 2-amino-, 2-acetamido-, 1-amino-4-nitro- and 2-amino-1-nitro-), biphenyls (2-amino-, 2-acetamido-, 4-amino- and 4-acetamido-), fluorenes (2-amino- and 2-acetamido-), anthracenes (1-amino-, 1-acetamido-, 2-amino- and 2-acetamido-), 3-aminofluoranthene, 1-aminopyrene and 6-aminochrysene. None of the compounds were mutagenic when tested without S9. With S9, 15 of 19 were mutagenic for TA98 and 16 of the 19 were mutagenic for TA100. Overall, 2-aminoanthracene was the most potent mutagen. When compared to the parent amines, the respective acetamido derivatives were consistently less mutagenic.

A community-based epidemiologic study of health sequelae of exposure to hydrofluoric acid

An accident at an oil refinery in Texas City, Texas, released around 40,000 lb of hydrogen fluoride, exposing the community to the highly toxic and corrosive substance. A population-based epidemiologic study was conducted to evaluate the impact of the accident on the health of the community. Exposure assessment was done using a multipronged approach through a door-to-door survey of 10,811 individuals. A symptom survey resulting in 1994 completed interviews was conducted with a stratified random sample selected from the exposure study database. The sampling was balanced with respect to age, gender, and predisposition across the three ordinal exposure categories. The results show a strong dose relationship (P < 10(-4)) between the exposure and symptoms reported following the accident and 2 years later, most notably breathing and eye symptoms. However, substantial improvement in health was reported over the 2-year period regardless of the level of exposure. Problems of recall bias and behavioral sensitization are considered and it is recognized that the study may have overestimated the effect. It is also recognized that the study may not have completely unraveled the relative importance of exposure and host response in health outcome, since the two were probably conflated in the exposure measure. Nevertheless, the independence of predisposition and reported level of exposure, the magnitude of effect and its consistency, the unmistakable dose response, the large sample size, and the mutual corroboration of various findings make it difficult to dismiss the interpretation that the hydrofluoric acid exposure indeed caused health problems in the community that continued for at least 2 years after the accident.

Sublethal and lethal toxicity of aluminum industry effluents to early developmental stages of the Crassostrea gigas oyster

The toxicity of the effluent from an aluminum plant on Crassostrea gigas oyster embryogenesis (lethal effects) and larval growth (sublethal effects) was tested. Liquid and solid phases of the effluent were separately tested, and effects of mixing during exposure were also evaluated. The effluent was highly toxic, causing abnormal embryogenesis at 0.03 to 1 g 1−1 and reduced growth at 0.01 to 0.3 g/l. The solid fraction was markedly more toxic than the liquid fraction. Mixing during exposure consistently increased both lethal and sublethal toxicity. Considering the trace metal content of the effluent, Hg is suspected to be primarily responsible for the toxicity, although synergistic effects of Al, Fe, and Cr cannot be discarded. Experimental evidence shows that bioavailable metal species were present not only in the liquid phase as soluble ions, but most importantly, bound to sediment particles. Based on the present data, uncontrolled disposal of aluminum plant effluent may be a major hazard to the environment, involving early life stages and recruitment in marine biota.

Developmental, cytogenetic and biochemical effects of spiked or environmentally polluted sediments in sea urchin bioassays

Sea urchin embryos and gametes have been utilised in toxicity testing for complex mixtures such as sediment samples. A number of toxicity endpoints can be evaluated by means of sea urchin bioassays, including developmental defects, changes in fertilisation success, offspring quality, and cytogenetic abnormalities. The present investigation has attempted to develop new methods focussing on a relationship between the well-established procedures based on embryological and cytogenetic endpoints, and a new approach based on measurements of redox activities in developing sea urchin larvae, by means of chemiluminescence methods and the measurement of reduced glutathione levels. The aim of this study was to evaluate the toxicity of either spiked or environmentally occurring sediment. Spiking was carried out by using some selected inorganics [Cd(II), Cu(II), Al(III) and Fe(III)] and a herbicide, pentachlorophenol (PCP). Environmental sediments were tested on samples collected in a series of sentinel sites in the Mediterranean, North Sea and Baltic Sea.

NONSUNLIGHT RISK FACTORS FOR MALIGNANT MELANOMA PART I: CHEMICAL AGENTS, PHYSICAL CONDITIONS, AND OCCUPATION

The role of sunlight in the etiology of malignant melanoma (MM) has been established. There is a rapidly growing literature that identifies many other MM risk factors besides sunlight. Part I of this review focuses on recognized nonsunlight risks for MM that include occupational and environmental exposure to a variety of chemical agents and physical conditions. Although it is possible to separate sunlight from nonsunlight risk for workplace-related MM, most studies have not investigated this interrelationship. Host factors for MM such as immunity and genetic risk as well as the strategies for preventing workplace MM are discussed in Part II,