Reproductive hazards, effects

No studies have been conducted to evaluate the reproductive effects of endrin aldehyde or endrin ketone in humans or animals via the inhalation, oral, and dermal routes of exposure. Additional animal studies and further human case studies are needed to determine the potential reproductive hazard and to determine threshold levels for effects that may exist via all three of these routes of exposure. 

The risk characterization is carried out by quantitatively comparing the outcome of the hazard (effects assessment) to the outcome of the exposure assessment, i.e., a comparison of the NOAEL, or LOAEL, and the exposure estimate. The ratio resulting from this comparison is called the Margin of Safety (MOS) (MOS = N(L)OAEL/Exposure). This is done separately for each potentially exposed population, i.e., workers, consumers, and man exposed via the environment, and for each toxicological endpoint, i.e., acute toxicity, irritation and corrosion, sensitization, repeated dose toxicity, mutagenicity, carcinogenicity, and toxicity to reproduction. 

Lead exposure can produce a number of other effects. One of the most common effects is on the red blood cells, which results in anemia. The red blood cells become fragile and hemoglobin synthesis is impaired. Changes in the red blood cells and some enzymatic changes were used as a marker for lead exposure. Similar to other metals, lead adversely affects kidney function, but this is now rare with reductions in occupational exposure. Several studies have demonstrated that elevated lead exposure is related to elevated blood pressure levels, particularly in men. There appears to be a weak association between lead exposure and increased incidence of lung and brain cancer. Lead exposure is a reproductive hazard for both males and females. In males, lead affects sperm count and sperm motility, resulting in decreased offspring. 

CERHR web site has information about potentially hazardous effects of chemicals on human reproduction and development. ... 

The February 1987 update of the October 1985 RTECS list of chemicals which cause reproductive hazards, had 6,917 entries. We selected the following T codes T01-T09 (paternal effects), T25 (postimplantation mortality), T31-T59 (effects on embryo or fetus, and specific developmental abnormalities), and T65 (transplacental tumorigenesis). All but the first ones (T01-T09) would fit into a classical definition of teratogens. The paternal effects were included in line with the recommendation by Schardein (vide supra), and also to incorporate the newest data on this long neglected subject. 

It should be emphasized that this kind of comparison is quite theoretical, and it does not provide absolute unsafe exposures, nor does it specify safe levels. However, with the present understanding of the animal experiments it would appear prudent to lower the TLV values for the compounds for which the human exposure may be up to 1/100 of the effective human dose. Even though the extrapolation from animal tests is compounded by uncertainties, the revision of the hygienic standards concerning the pregnant worker appears justifiable in such cases. With ever-increasing female participation in the work force, more emphasis should be placed on reproductive hazards and their prediction, in the absence of adequate epidemiologic data, from experimental results. 

The isolated aldehyde citral can be a skin irritant or sensitizer and has been implicated in reproductive disorders. In Citrus Union (lemon oil) it makes up to 5% of the composition. It has been shown that the hazardous effects are markedly reduced by the presence of the terpenes d-limonene and a-pinene also present in the oil. 

Sufficient versus insufficient evidence. Sufficient evidence includes data that collectively provide enough information to judge whether or not reproductive hazard exists within the context of effect as well as dose, duration, timing, and route of exposure. Both human and animal evi-... 

Apart from the acute toxic effects of high concentrations of the more volatile solvents, there are health hazards from the long-term (chronic) exposure to low levels of solvents. Reproductive effects that are associated with chronic exposure to some solvents used in laboratories are shown in Table 11.8. Evidence from animal studies suggests there are reproductive hazards from handling other solvents. Eor example ... 

Some reproductive toxic effects cannot be clearly assigned to either impairment of sexual function and fertility or to developmental toxicity. Nonetheless, chemicals with these effects would be classified as reproductive toxicants with a general hazard statement. 

Hazard Human systemic effects reported. A reproductive hazard. 

One oral continuous breeding study was perfonned in mice, a drinking water study (Heindel et al. 1990) that has also been summarized in Morrissey et al. (1988, 1989). An oral reproductive study in rats and reproductive studies in two species conducted by the inhalation and dermal routes (which are the two routes most relevant for humans) would help to complete tlie picture of reproductive effects of 2-butoxy-ethanol in animals and help to determine whether 2-butoxyethanol exposure presents a reproductive hazard to humans. 

Reproductive Effects. Limited data indicate that menstrual disturbances in women and effects on sperm morphology and production, which are effects that can result in difficulty in a couple conceiving, may be associated with exposure to PCBs. Overall, the studies of reproductive end points in humans are limited however, the weight of the existing human and animal data suggests that PCBs present a potential reproductive hazard to humans. 

Parental Hazards (Effects). For assessment of reproductive and developmental risk, parental hazards, both paternal and maternal, must be identified and evaluated. Parental hazards can be expressed as altered nutritional state, functional impairment, and systemic toxicity. Because of possible indirect affects, knowledge and evaluation of non-reproductive/non-developmental toxicity studies are useful. This information is available by examination of subchronic and chronic toxicity studies. 

Toluenediamine is classed as toxic. The oral LD q for animals is between 270—350 mg/1 body weight (45). TDA is readily absorbed through the skin and this is the major route of human exposure. Several studies have shown the 2,4 isomer of TDA to be carcinogenic for rats and mice, but tests on the 2,5 and 2,6 isomers were not positive. AH three of the isomers have been shown to be mutagenic (45). Results of limited smdies on the reproductive hazards for male workers are equivocal, but animal experiments have shown TDA to cause adverse reproductive effects (45). 

The most common phthalate plasticisers are di-2-ethyl hexyl phthalate (DEHP), di-isodecyl phthalate (DIDP), and di-isononyl phthalate (DINP). Phthalate use has been controversial for years becanse of its snspected health hazards, especially in the case of DEEIP. In both wildlife and laboratory animals, phthalates have been linked to a range of reproductive health effects, with claims that most of them can function as an endocrine disrupting chemical (EDC), and also as cancer-causing agents (specifically in the liver and kidneys). Snch negative effects that phthalates are suspected to have on health have been attribnted to short ester chains (< C9). In fact, phthalates are already distributed worldwide in the environment. Some phthalates are even found in deep-sea jellyfish 1,000 meters below the surface of the North Atlantic Ocean. A number of studies have shown that most people are probably contaminated by substantial quantities of these chemicals, and yet for hnmans, no safe level of exposure to phthalates has been determined. There are also claims about the leaching of certain phthalate plasticisers from biomedical plastics (e.g., intravenous tubes) and hence directly into the patients bloodstream. In one snch stndy, it was shown that about 60% of the DEHP/DOP had migrated to the patient, while almost all of the bis (2-ethylhexyl) adipate (DOA) has been retained in the tnbe [28]. 

The overall toxicological profile of florasulam is very favorable. It is not acutely toxic, does not pose an inhalation hazard, nor is it a skin sensitizer. No evidence of mutagenic or carcinogenic potential was obtained from any study. It showed no teratogenic effects in either rats or rabbits. Tests also indicate that florasulam is not a reproductive hazard or concern. 

There is considerable uncertainly about the number of workers actually exposed to harmful levels of workplace reproductive hazards and the number of resulting adverse health effects. However, a substantial number of scientific studies have found these effects in specific groups of workers following both maternal and paternal exposure. 

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