Toxicity to humans

Aldrin is insecticidally active as a contact and stomach poison against a wide range of soil pests. It is non-phytotoxic and does not cause taint. Aldrin is toxic to humans and animals and is now less used. 

Phytoalexins are low molecular weight compounds produced in plants as a defense mechanism against microorganisms. They do, however, exhibit toxicity to humans and other animals in addition to microbes (30). Coumarins, glycoalkaloids, isocoumarins, isoflavonoids, linear furanocoumarins, stilbenes, and terpenes aU. fall into the category of phytoalexins (31). Because phytoalexins are natural components of plants, and because their concentration may increase as a response to production and management stimuli, it is useful to recogni2e the possible effects of phytoalexins in the human diet. 

W. J. Hayes, Jr., and E. R. Laws, Jr., eds.. Handbook of Pesticide Toxicology, Academic Press, Inc., San Diego, Calif., 1990. Three volume set provides detailed toxicological profiles of more than 250 insecticides, herbicides, and fungicides each compound described by identity, properties, and uses toxicity to humans, laboratory animals, domestic animals, and wildlife includes comprehensive coverage of diagnosis, treatment, prevention of injury, effects on domestic animals, wildlife, and humans - ISjOOO references. 

Environmentally, carbon blacks are relatively stable and unreactive. There is no evidence that these materials are toxic to humans or animals. 

Toxic to individual species or broadly hazardous Pesticides, fungicides, herbicides, insecticides, fumigants Toxic to humans Chronic or acute... 

The CESARS database contains comprehensive environmental and health information on chemicals. It provides detailed descriptions of chemical toxicity to humans, mammals, aquatic and plant life, as well as data on physical chemical properties, and environmental fate and persistence. Each record consists of chemical identification information and provides descriptive data on up to 23 topic areas, ranging from chemical properties to toxicity to environmental transport and fate. Records are in English. Available online through CCINFOline from the Canadian Centre For Occupational Health and Safety (CCOHS) and Chemical Information System (CIS) on CD-ROM through CCIN-FOdisc. 

Hazard or event identification provides information on situations or chemicals and Uieir releases Uuit can potentially hann lire enviromnent, life, or property. Information Uiat is required to identify hazards includes chemical identities, quantities and location of chemicals in question, chemical properties such as boiling points, ignition temperatures, and toxicity to humans. There are several metliods used to identify some of the liazards. Some of these metliods are discussed in Uiis cliapter. 

Microbiocides may be toxic to humans therefore, care must be taken when used. When selecting the microbiocide, the field engineer can obtain pertinent information on chemicals from the service company providing the chemicals. The microbiocide selected must be compatible with the system in which it is being used. Some chemicals such as quaternary amines have dual functions one as microbiocides and the other as film-forming corrosion inhibitors. Insufficient concentrations of this type of chemical may not be enough to coat the whole surface of metal and can cause pitting corrosion. The selection must also depend on chemicals that can produce the desired control in minimum time limits and... 

The first of the antibiotics that found practical use as a therapeutic was penicillin. The success of penicillin initiated a vast screening process all over the world, which resulted in the isolation of a large number of antibiotic substances from various natural sources. Many of these compounds were produced by micro-organisms and prove to be lethal for other micro-organisms. Many of these compounds were also very toxic to humans and could not be used therapeutically. Nevertheless a large number of classes of useful compounds were produced. The chemical structures of members of some of the most important classes are shown in Figure 6.1. 

Once an antibiotic producer has been identified, the next stage is to produce sufficient of the antibiotic to evaluate its potential for therapeutic use. Questions, such as, is it toxic to humans , is it effective against disease organisms , does it possess suitable characteristics (for example solubility, chemical stability) for use as a medicine , need answering. Let us assume that a new, potentially useful antibiotic has been discovered. The key questions then become, how can the desired material be produced in the most cost effective way is it possible to produce variants of the antibiotic which have desirable properties, such as greater effectivity against infection, cheaper ways to produce it or increased stability ... 

Melarsoprol, a trivalent organic melaminophenyl arsenic compound, kills intracerebral parasites of both T. brucei gambiense and T. brucei rhodesiense. Melarsoprol accumulates via an adenosine/adenine transporter in trypanosomes and is believed to inhibit glycolytic enzymes. Melarsoprol leads to a rapid lysis of trypanosomes. Melarsoprol is highly toxic to humans. 

The substance may have effects on the liver, resulting in liver impairment. Animal tests show that this substance possibly causes toxicity to human reproduction or development. 

Tables 2.6 and 2.7 give examples of the modes of action of pollutants in animals and in plants/fungi, respectively. It is noteworthy that many of the chemicals represented are pesticides. Pesticides are designed to be toxic to target species. On the other hand, manufacturers seek to minimize toxicity to humans, beneficial organisms and, more generally, nontarget species. Selective toxicity is an important issue. Regardful of the potential risks associated with the release of bioactive compounds into the environment, regulatory authorities usually require evidence of the mode of toxic action before pesticides can be marketed. Other industrial chemicals are not subject to such strict regulatory requirements, and their mode of action is frequently unknown.

Oxidative catalytic converters are used to reduce CO and HCs originating from imperfect combustion in engines. At certain temperatures, these converters may also oxidize NO to NO2. Original equipment manufacturer (OEM) particle filters (PFs) employ NO2 to oxidize trapped soot at lower temperatures. However, the excess NO2 may escape from the system as tailpipe emissions. NO2 is very toxic to humans, and it also has impacts on atmospheric ozone-forming chemistry. Alvaraz et al. have stated that the primary NO2 emissions of modern diesel cars are increasing [76]. 

The sub-phyllum Anthozoa (6,500 species) contains the classes Alcyonaria (soft corals, sea fans, sea pens, sea pansies), Zoantharia (sea anemones and true corals), and Ceriantipatharia. The Scleroactinia (Madreporaria-true or stony corals) build the massive coral reefs and atolls which occur in tropical waters. According to Hashimoto (75), toxicity to humans is mainly found in the fire or stinging corals (Millepora sp.) and, to a lesser extent, in the stony corals (Goniopora sp.). 

Benchmark 4 Prefer - Safer Chemical. Only organic chemicals with low inherent toxicity to humans and wildlife, that do not bio accumulate, and rapidly and completely degrade to benign degradation products or metabolites reach Benchmark 4. These are chemicals that would meet the principles of green chemistry that relate to hazard. 

Many were acutely toxic and/or chronically toxic to humans, domestic animals, and wildlife. Their ability to cause tumors, at least in laboratory animals, was of particular concern. 

Residue chemists will need to continue to improve the speed of analysis. In situ measuring methods that can be applied in the field or processing plant or retail outlet would be particularly useful, so that decisions can be made rapidly which might avert toxicity to humans or wildlife, potential residue problems or unnecessary economic loss. 

Dinitrophenol is a member of the aromatic family of pesticides, many of which exhibit insecticide and fungicide activity. DNP is considered to be highly toxic to humans, with a lethal oral dose of 14 to 43mg/kg. Environmental exposure to DNP occurs primarily from pesticide runoff to water. DNP is used as a pesticide, wood preservative, and in the manufacture of dyes. DNP is an uncoupler, or has the ability to separate the flow of electrons and the pumping of ions for ATP synthesis. This means that the energy from electron transfer cannot be used for ATP synthesis [75,77]. The mechanism of action of DNP is believed to inhibit the formation of ATP by uncoupling oxidative phosphorylation. 

Choice of Solvent. As indicated by Averell and Norris (1), and independently confirmed by the authors, technical benzene is a superior stripping solvent for parathion residues. It is almost completely miscible with technical grade parathion at room temperatures, it is universally available and low in cost, it is readily volatile, it fails to contribute to storage decomposition (6), it is a good solvent for plant oils and waxes, and it is immiscible with water. On the other hand, benzene is highly flammable and its vapors are very toxic to human beings, especially as a chronic toxicant even in small doses. 

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