Occupational and Environmental Aspects of Organophosphorus Compounds

Abstract

Besides being a potential risk to humans and other living organisms, organophosphorus (OP) compounds also poses a risk to the environment. Production and placing pesticides on the market are under national and international legislative framework, although in many developing countries the regulation is still inadequate or not properly enforced. Occupational exposure to OPs includes any job which involves either direct or indirect contact with OP compounds, while public exposure to OPs may occur through contaminated food or from hand-to-mouth contact with contaminated surfaces, inhalation and dermal contact.

The aim of this chapter is to present a comprehensive review of control and regulation measures, risk assessment methods, types and modality of occupational and environmental exposure to OPs, and ecotoxicology of these compounds.

Review of the literature on OP exposure in electronic bibliographic databases, textbooks, and Internet sources was done.

The acute high-dose effects of OPs are well known and include neurological dysfunction due to the inhibition of acetylcholinesterase (AChE), while effects of low-level exposure are still a matter of controversy.

Advances in analytical methods help scientists to find new biomarkers of exposure and tools for biological monitoring and regulations of occupational exposure.

Glossary

AAPCC—

American Association of Poison Control Centers

ADI—

A value used for non-carcinogenic substances which represents a daily dose that is very likely to be safe over an extended period of time.

AOEL—

Acceptable operator-exposure level is the level of daily exposure that would not cause adverse effects in operators.

ARfD—

Acute reference dose is the amount of a substance that can be consumed at one meal or on one day with practical certainty.

Biocide—

Active substance and preparation containing one or more active substances, put up in the form in which they are supplied to the user, intended to destroy, deter, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means.

BMD—

Benchmark dose is defined as the dose that corresponds to a specified,

predetermined change in an adverse response (5–10 %) compared to background.

BMDL—

Benchmark dose lower confidence limit is statistical lower confidence limit for a dose that produces a predetermined change in response rate of an adverse effect compared to background

Cholinergic syndrome—

The clinical syndrome that results from excessive stimulation of acetylcholine receptors

CMR—

Carcinogenic, mutagenic and reproductive toxic compounds Cumulative risk is the likelihood of an occurrence of an adverse health effect resulting from all routes of exposure to a group of substances sharing a common mechanism of toxicity.

CWA—

hemical warfare agents

DAP—

Dialkyl phosphate

DEDTP—

Diethyldithiophosphate

DEP—

Diethylphosphate

DETP—

Diethylthiophosphate

DMDTP—

Dimethyldithiophosphate

DMP—

Dimethylphosphate

DMTP—

Dimethylthiophosphate

Dose-response assessment—

The determination of the relation between the magnitude of exposure and the probability of occurrence of the health effects.

EFSA—

European Food Safety Authority

EPA—

Environmental Protection Agency’s

Exposure assessment—

The determination of the extent of human exposure.

FIFRA—

Federal Insecticide, Fungicide and Rodenticide Act

FQPA—

Food Quality Protection Act

Hazard—

The inherent ability of a substance to cause an adverse effect under defined conditions of exposure.

Hazard identification—

The determination of whether a particular chemical is or is not causally linked to particular effect(s) on health.

Hormesis phenomenon—

Dose-response phenomenon characterized by a low dose stimulation, high dose inhibition.

ILSI—

International Life Science Institute

IMS—

Intermediate syndrome

IPCS—

International Program for Chemicals Safety

LOAEL—

Lowest-Observed-Adverse-Effect-Level—The lowest experimental dose at which there is a statistically or biologically significant increase in the frequency or severity of adverse health effect in the exposed population compared with an appropriate, unexposed population.

LTLL—

long term low level exposure

MRL—

Maximum residue levels are the upper legal levels of a concentration for pesticide residues in or on food or feed based on good agricultural practices and to ensure the lowest possible consumer exposure.

NOAEL—

No-Observed-Adverse-Effect-Level—The highest experimental dose at which there is no statistically or biologically significant increase in frequency or severity of adverse health effect in the exposed population compared with an appropriate, unexposed population.

OEL—

Occupational exposure limit is a limit on the concentration of a hazardous substance in workplace air.

TLV—

Threshold limit value is the concentration of the substance below which no adverse health effects are expected to occur for workers assuming exposure for 8 h per day, 40 h per week.

OPIDN—

OP-induced delayed polyneuropathy

Plant protection products—

Any chemical or biological agent used for controlling, preventing, killing or otherwise discouraging plant pests.

Risk—

The probability that an adverse effect will occur under a particular condition of exposure.

Risk assessment—

A scientifically based process of evaluating the toxic properties of a chemical and conditions of human exposure to it in order to ascertain the likelihood that exposed people will be adversely affected and to characterise the nature of these effects.

Risk characterisation—

The description of the nature and often the magnitude of human risk, including attendant uncertainty.

Risk management—

The decision-making process that includes consideration of technical, scientific, social, economic, and political information.

Risk mitigation—

The process of reduction of either probability or consequences of a risk

RPF—

Relative potency factor. The ratio of the toxic potency of a given chemical to that of an index chemical. Relative potency factors are used to convert exposures of all chemicals that share a common mechanism of action, into their exposure equivalents of the index chemical.

Target organ—

Any organ that is subject to the action of an agent.

TESS—

Toxic Exposure Surveillance System