Arthropods comprise more than 1 million species of insects and thousands of species of ticks, mites, spiders, scorpions and centipedes. Bees, ants, wasps and scorpions sting and inject venom; mosquitoes and ticks suck blood and transmit diseases; and the scales and hairs from insect bodies can irritate the eyes and skin, as well as tissues in the nose, mouth and respiratory system. Most stings in humans are from social bees (bumble bees, honey bees). Other stings are from paper wasps, yellow jackets, hornets and ants.
Arthropods can be a health hazard in the workplace (see table 1), but in most cases, potential arthropod hazards are not unique to specific occupations. Rather, exposure to arthropods in the workplace depends on geographic location, local conditions and the time of year. Table 2 lists some of these hazards and their corresponding arthropod agents. For all arthropod hazards, the first line of defence is avoidance or exclusion of the offending agent. Venom immunotherapy may increase a person’s tolerance to arthropod venom and is accomplished by injecting increasing doses of venom over time. It is effective in 90 to 100% of venom hypersensitive individuals but involves an indefinite course of expensive injections. Table 3 lists normal and allergic reactions to insect stings.
Table 1. Different occupations and their potential for contact with arthropods that may adversely affect health and safety.
|
Occupation |
Arthropods |
|
Construction personnel, environmentalists, farmers, fishers, foresters, fish and wildlife workers, naturalists, transportation workers, park rangers, utility workers |
Ants, bees, biting flies, caterpillars, chiggers, centipedes, caddisflies, fly maggots, mayflies, scorpions, spiders, ticks, wasps |
|
Cosmetics manufacturers, dock workers, dye makers, factory workers, food processors, grainery workers, homemakers, millers, restaurant workers |
Ants; beetles; bean, grain and pea weevils; mites; scale insects; spiders |
|
Beekeepers |
Ants, bumble bees, honey bees, wasps |
|
Insect production workers, laboratory and field biologists, museum curators |
Over 500 species of arthropods are reared in the laboratory. Ants, beetles, mites, moths, spiders and ticks are especially important. |
|
Hospital and other health care workers, school administrators, teachers |
Ants, beetles, biting flies, caterpillars, cockroaches, mites |
|
Silk producers |
Silk worms |
Table 2. Potential arthropod hazards in the workplace and their causative agent(s)
|
Hazard |
Arthropod agents |
|
Bites, envenomation1 |
Ants, biting flies, centipedes, mites, spiders |
|
Sting envenomation, venom hypersensitivity2 |
Ants, bees, wasps, scorpions |
|
Tick toxicosis/paralysis |
Ticks |
|
Asthma |
Beetles, caddisflies, caterpillars, cockroaches, crickets, dust mites, fly maggots, grain mites, grain weevils, grasshoppers, honeybees, mayflies, moths, silk worms |
|
Contact dermatitis3 |
Blister beetles, caterpillars, cockroaches, dried fruit mites, dust mites, grain mites, straw itch mites, moths, silk worms, spiders |
1 Envenomation with poison from glands associated with mouthparts.
2 Envenomation with poison from glands not associated with mouthparts.
3 Includes primary irritant and allergic dermatitis.
Table 3. Normal and allergic reactions to insect sting
|
Type of response |
Reaction |
| I. Normal, non-allergic reactions at the time of the sting |
Pain, burning, itching, redness at the sting site, white area surrounding the sting site, swelling, tenderness |
| II. Normal, non-allergic reactions hours or days after sting |
Itching, residual redness, small brown or red damage spot at sting site, swelling at the sting site |
|
III. Large local reactions |
Massive swelling around the sting site extending over an area 10 cm or more and increasing in size for 24 to 72 hours, sometimes lasting up to a week or more |
|
IV. Cutaneous allergic reactions |
Hives anywhere on the skin, massive swelling remote from the sting site, generalized itching of the skin, generalized redness of the skin remote from the sting site |
|
V. Non life-threatening systemic |
Allergic rhinitis, minor respiratory symptoms, abdominal cramps |
|
VI. Life-threatening systemic allergic reactions |
Shock, unconsciousness, hypotension or fainting, difficulty in breathing, massive swelling in the throat. |
Source: Schmidt 1992.