Ticks, poison ivy, noise and vibration: health hazards of tree work

This page describes what agencies publish. It is not medical advice. Questions about a bite, a rash, a hearing test or a sunburn belong with a doctor or the health agency in your country. The numbers and rules on these pages change.

What the agencies group together

The US National Institute for Occupational Safety and Health (NIOSH) has an outdoor workers hazards page. It says outdoor workers meet different hazards depending on the type of work, the region, the season and the time spent outside. It lists these.

Physical. Extreme heat, extreme cold, noise that "can cause permanent hearing loss", sun exposure and wildland fire smoke.
Biological. Mosquitoes and ticks that spread disease, venomous snakes, spiders, scorpions and stinging insects, and poisonous plants.

The same page says employers should train outdoor workers to identify hazards and ways to prevent or control exposures. It also says small businesses may lack resources or time for safety activities. The sections below take the hazards one at a time.

Ticks and Lyme disease

United States

NIOSH has a page on tickborne diseases in workers. It says worksites with or near woods, bushes, high grass or leaf litter are likely to have more ticks. It says ticks may be active all year in warmer regions and are most active in spring, summer and fall in the United States. Forestry, landscaping, park management and utility line work are on its list of jobs at risk. For prevention it points to clothing, EPA-registered repellents, daily skin and clothing checks, and a doctor if symptoms appear.

Canada

The Canadian Centre for Occupational Health and Safety (CCOHS) says in its Lyme disease fact sheet that Lyme disease is an occupational concern for people who work outdoors, and it lists forestry workers among those at risk. It names two tick species that spread it in North America, the blacklegged tick and the western blacklegged tick. It says signs may appear 3 to 30 days after a bite and cites the Public Health Agency of Canada (PHAC) on how quickly removing a tick matters. It attributes the timing advice to PHAC, and says signs vary greatly from person to person.

United Kingdom

The NHS Lyme disease page says ticks that may cause Lyme disease are found all over the UK, and that high-risk places include grassy and wooded areas in southern England and the Scottish Highlands. It says the rash can appear up to 3 months after a bite but usually appears within 1 to 4 weeks. It says not all ticks in England carry the bacteria.

Australia

The Sydney Children's Hospitals Network, a New South Wales Government health network, has a tick bites factsheet. It says tick saliva can carry diseases, cause paralysis and trigger severe allergic reactions, and that the longer a tick feeds, the higher the risk of allergy. It is written for children, and a state health department is the source for adult and worker advice.

Poisonous plants

On the NIOSH site, the poisonous plants page names poison ivy, poison oak and poison sumac. It lists forestry workers among those at risk and says these plants are found throughout the United States except Alaska and Hawaii. It says the plants release an oil called urushiol when damaged or burned, and that workers can be exposed three ways:

direct contact with the plant;
indirect contact, such as touching tools or clothing that carry the oil;
breathing particles from burning plants.

It says an amount of urushiol smaller than a grain of salt causes a rash in 80 to 90 percent of adults, and that the oil can stay active on the surface of objects for up to 5 years. It notes the "leaves of three" rhyme does not apply to poison sumac, which usually has clusters of 7 to 13 leaves, and that burning these plants can irritate the lungs. The page lists first aid and says to get medical help in severe cases.

Other countries have their own plants of concern, and the national or state health agency is the place to look.

Noise

Country	What the agency says	Where
United States	Hearing conservation program at 85 dBA, 8-hour average, general industry. Engineering or administrative controls above 90 dBA.	OSHA, 29 CFR 1910.95
United Kingdom	Action values 80 and 85 dB(A). Exposure limit value 87 dB(A).	HSE, Control of Noise at Work Regulations 2005
New Zealand	Hearing loss from work noise is preventable and irreversible.	WorkSafe New Zealand

On the OSHA site, the occupational noise exposure page says exposure over 85 decibels can damage hearing and gives a rule of thumb: if you need to raise your voice to speak to someone 3 feet away, noise might be over 85 dBA. It describes 1910.95 as the general industry standard and says the standard's hearing conservation program covers exposure monitoring, hearing tests, hearing protection and training.

On the HSE site, the tree work noise page says exposure to many sources such as chainsaws, powered hand tools and wood chippers has a cumulative effect, even if a worker is exposed to each for a short time. It gives a test of its own: you have a noise problem if you have to raise your voice to hold a normal conversation about 2 metres apart for part of the day. HSE's noise regulations page sets out the 80, 85 and 87 dB(A) values and says hearing checks are required for workers regularly exposed above 85 dB(A).

On the WorkSafe New Zealand site, the noise page says hearing loss is preventable and irreversible. The page shows September 17, 2018 as its last update. SafeWork NSW lists noise among tree work risks (see the Australia section below).

Hand-arm vibration

On the HSE site, the hand-arm vibration page for forestry and arboriculture says vibration may come from chainsaws, brush-cutters and stump-grinders. It says long-term exposure to high levels can damage the hand, including vibration white finger and carpal tunnel syndrome. Its list of tools that create exposure also names clearing saws, hedge trimmers and earth augers.

Value	Level, daily A(8)	What HSE says
Exposure action value	2.5 m/s2	Technical and organisational measures to reduce exposure
Exposure limit value	5 m/s2	Exposure above it is prohibited

The page says the regulations require four main actions from employers: identify risks, put measures in place to reduce them, give information and training, and run a health surveillance programme. It says controls must be introduced for jobs with a history of risk, such as forestry and arboriculture. It also says no personal protective equipment can be shown to reduce the risk and that anti-vibration gloves at best give a small reduction.

Heat

On the NIOSH site, the heat stress page says heat stress can result in heat stroke, heat exhaustion, rhabdomyolysis, heat cramps and heat rashes. Its risk factors include high temperature and humidity, direct sun, lack of acclimatization, dehydration, physical exertion, and clothing and personal protective equipment.

Sun

On the NIOSH site, the sun exposure page says working outdoors in sunlight can increase the risk of sunburn and skin cancer. It says UV is generally highest in summer and between 10:00 a.m. and 4:00 p.m., and that workers are at risk even on cloudy days. It also says UV can damage the eyes and that some medications raise sensitivity to sunlight.

In Australia, SafeWork NSW's tree work page lists sun exposure and noise among the major risks of tree work, along with falls, falling objects, power lines and musculoskeletal disorders.

Stings, spiders and snakes

NIOSH says venomous snakes, spiders, scorpions and stinging insects are found in many regions and can be especially dangerous to workers who are allergic to the venom.

Where each agency's page sits

Country	Hazards covered	Agency
United States	Ticks, plants, noise, heat, sun, stings	NIOSH, OSHA
Canada	Lyme disease	CCOHS
United Kingdom	Lyme disease, noise, vibration	NHS, HSE
Australia	Ticks, sun, noise, tree work risks	NSW Health network, SafeWork NSW
New Zealand	Noise	WorkSafe New Zealand

Rules about who must do what differ by country and sometimes by state or province. For the safety rules themselves, see the guide on safety rules for tree work country by country.