Scientific and medical research shows that people of Asian and African ethnicity are genetically more susceptible to naphthalene poisoning via inhalation.
@PHE_London representative Robie Kamanyire falsely claimed this is from ingestion only.
youtube.com/embed/ZdTj-l3S…
@PHE_London 50% ingested, 50% inhaled vapours.
onlinelibrary.wiley.com/doi/epdf/10.11…
@PHE_London Roby Kamanyire has emailed the following response to my query. 
@PHE_London It beggars belief, his response. Firstly, he admits that people of Asian and African origin (or 'people with a Glucose-6-phosphate dehydrogenase (G6PD) deficiency' as he calls them) are at risk.
Then restates his false claim that it's all about children swallowing mothballs. Or is he now referring simply to long-term health impacts in general? I've asked him for his sources, but he's on holiday now until 7 August!
The source I found is a literature review from 2013, which quite clearly talks about inhalation as the main risk (and even the single research source linked to for the genetic factor describes inhalation as the main pathway, as well as ingestion).
Then to exclude the soil hospital (which is/was always claimed to be the main source of the odour), and by which measurement PHE themselves stated that levels of naphthalene were well above legal limits and need to be 'urgently reduced' to prevent long-term exposure. Astounding!
Unroll @threadreaderapp