I've recently become a qualified electrician and I work for myself. The main type of wok is in old domestic dwellings with lat and black horse hair plaster. As with the nature of my job, a lot (and I mean a lot!) of dust is created when chasing out the walls for cables to be buried beneath. I try my best to wear a dust mask when needed but it's more or less impossible to not breath in the dust particles and still at the end of the day I have a mouth that tastes dusty and have a very black nasal passage. Obviously breathing in dust isn't good for you but would love to know if what I'm describing is really bad for you. If my lungs will be affected long term or chemical content of the plaster etc. Looking forward to finding something out. Cheers!

I found this out about horse hair plaster:

http://www.bricksandbrass.co.uk/diy/diy_dangers.php


Anthrax in Plaster
Plaster usually contains horsehair and, before controls were introduced in 1895, could contain anthrax spores. Although there are no recorded cases of infections from this source, when removing plaster you should take reasonable precautions.

English Heritage recommend that you should:

■cover all cuts, abrasions and other wounds with waterproof dressings to prevent infection
■keep hands and fingernails clean and avoid hand-to-mouth contact during work
■wear protective clothing (such as disposable gloves, overalls, eye protection, dust masks) appropriate to the task in hand. Dust masks should provide protection against infectious agents (FFP3 type, European Standard EN 149).
■not eat or drink in work areas and wash hands thoroughly before handling food
■keep first aid kits well-maintained and to hand, and ensure they contain waterproof dressings
■if removing old plaster, ensure that it is disposed of in accordance with local and statutory national controls, and that the generation of dust is minimised (e.g. by vacuum cleaning using a high-efficiency filter instead of dry-brush cleaning).
■keep surrounding areas clean and dust-free
■ensure that personal are informed of the risk and risk management strategy.

While anthrax may be a longshot possibility, you should be more concerned with lead paint, I am sure had been applied to the plaster over the years.

Safety and Health Topics: Lead (http://www.osha.gov/SLTC/lead/)

I don't have any info at my finger tips, recently I recall that anyone working in old homes must be trained to work with lead paint.

It's the plaster dust or any particulates you inhale, including dirt (the black in your nose), and various kinds of new and old insulation (cellulose, rock wool, fiberglass), more than whether the wall is gypsum board, horsehair or lint plaster.

My husband is an electrician as well, and we live in a house built in the late 1870's. When we decided to renovate, we found wall after wall of horsehair plaster that had been sheet-rocked over multiple times. The dust is the most hideous thing I have ever dealt with. Due to some unfortunate financial problems he had to halt right in the middle of our renovations. For 5 years we have been exposed to open walls containing horsehair plaster that continuously shed dust upon everything for the time it was open. Duct taping tarps and door frames, towels under doorways and even taping cracks in the walls. Nothing could keep the dust at bay. We have had no resulting health problems (even though we continuously breathe and ingest small portions regularly since just walking around the house and closing doors will cause dust to shake loose). It falls through wall spaces and even flows out receptacles sometimes! But when working directly with it I have heard that a heavy-duty respirator is best.
As far as the anthrax goes, if you are indeed infected with it's spores, you would know relatively quickly. This is from a website called "How Things Work" describing inhaled anthrax symptoms.

Inhaled anthrax typically begins showing symptoms in seven to 10 days, although it could be as early as two to three days. It can take as long as 60 days after exposure to the anthrax spores for the disease to surface, however, and once the germination begins, the disease progresses very rapidly. It appears to come in two stages:

It begins with fever, cough, headache, vomiting, chills, weakness, abdominal pain, shortness of breath and chest pain. This first stage may last from a few hours to a few days. Then there may be a brief break in symptoms.
The second stage of the disease lasts anywhere from two to four days. The symptoms for the second stage include fever, difficulty breathing, sweating, a bluish discoloration of the skin, shock, and finally death.
So I wouldn't worry too much unless it's a REALLY old home.

BeccaG... old post I know but here's hoping! You say you and your husband were renovating. We are too, whilst also living in the house and I was worried about daily breathing in of dust! I am also paranoid about asbestos, as our house is old too. Is this something you and your fella worried about or did you get a renovation survey?
Thanks
Kris