Chemical compounds such as arsenic, mercury and organochlorine pesticides have been extensively used as preventive and curative conservation treatments for cultural and biological collections to protect them from pest and mould infestations. Most of the aforementioned compounds have been classified as carcinogenic, mutagenic and teratogenic and represent a health risk for staff exposed to contaminated objects. A total of 30 compounds were analysed in settled dust, particulate matter and surrounding air collected at several locations in the natural history collections and adjacent rooms of the Museum für Naturkunde, Berlin (MfN, Natural History Museum, Berlin, Germany). Gas chromatography and mass spectrometry techniques were used to quantify dichlorodiphenyltrichloroethane (2,4′-DDT; 4,4′-DDT) and their metabolites (2,4′-DDE; 4,4′-DDE; 2,4′-DDD; 4,4′-DDD), hexachlorobenzene (HCB), 3 isomers of hexachlorocyclohexanes (α-HCH, β-HCH, γ-HCH), the degradation product of γ-HCH with similar toxicological profile, gamma-pentachlorocyclohexene (γ-PCH) and pentachlorophenol (PCP). Atomic absorption spectrometry was used to analyse arsenic and mercury. In order to assess the pathways of contamination with biocides in dust, formations of particulate matter during individual daily work activities, particle number concentrations (PNCs) were measured. Heavy element concentrations found at the MfN were higher than the organochlorine compounds. The maximum concentration of arsenic and mercury in dust was 3507 mg/kg and 32 mg/kg, respectively, and in air, 48 ng/m3 and 1.6 ng/m3, respectively. The maximum concentration of the sum of DDTs in dust was 2 mg/kg (not detected in air); for PCP, the maximum levels in dust and air were 0.65 mg/kg and 10 ng/m3, respectively; for γ-HCH, 130 mg/kg and 320 ng/m3, respectively; and finally, for γ-PCH, 2.1 mg/kg and 230 ng/m3, respectively. Twelve PNC measurements were obtained from seven different collection rooms and the diaries of the participants’ activities. PNCs were highly variable between work activities. Higher personal PNCs were associated with activities like opening storage boxes with prepared animals, reading old books or handling objects. This study has shown that taxidermic objects in museum collection may be a cause for arsenic exposure during handling of objects.