The phrase "affects the quantity and" is correct and usable in written English.
It can be used in contexts discussing how something influences or changes the amount of something else.
Example: "The new policy affects the quantity and quality of the resources available to the team."
Alternatives: "influences the amount and" or "impacts the volume and".
Groundwater is important in the overall water budget of a lake because it affects the quantity and quality of surface water and the ecological health of the lake.
Salt (Na+) stress constitutes an important environmental pressure, and elevated Na+ levels in agricultural land adversely affects the quantity and quality of crop plants (Buchanan et al. [2005]; Knäblein et al. [2006]; Atkinson and Urwin [2012]; Horie et al. [2012]).
Using two waves of survey data from a national sample of academic scientists and engineers across six disciplines in the United States, we investigate how network churn affects the quantity and quality of scientific production.
The purpose of this study was to determine how the amount of surgical insult affects the quantity and maturity of dentoalveolar bone around teeth that have been orthodontically moved.
The oxidation ability of NO2, NO, and N2O contained in NOx are different, and the change of diesel engine exhaust composition also affects the quantity and proportion of them.
In this work it is shown that the polyethylene viscosity can be of significant importance in ternary partial wetting when the interfacial driving force for partial wetting is weak and viscosity directly affects the quantity and size of PS droplets at the interface during annealing.
Switching attention between tasks and managing distractions takes up time and energy and can affect the quantity and quality of work.
The island's thin soil and inadequate rainfall adversely affected the quantity and quality of its sugar crop; these factors made production less profitable than on other Caribbean islands, where large areas of fertile soil and adequate rainfall created lucrative sugar plantations that evolved into societies with a large labouring class.
Even minor variations in environment or nutrition have the potential to affect the quantity and diversity of fungal metabolites.
